A few clarifications to the above:

The “Group Everywhere” option is greyed out if you only have two rooms/speakers. 
 

To group rooms, click the group icon (at bottom right of screen) after you have selected a room. The list of rooms available to group comes up. Select the rooms you want to have playing in sync from the same music source by tapping the circle to the right of roomname . 

The volume slider will by default adjust volume of all speakers in that group. Tap it and individual controls for each speaker will appear. 
 

In Sonos terminology, creating a “pair” of speakers is to create a stereo pair, and can only be done with two of the same model of speakers such as two Fives or two Ones (though a One and OneSL can be paired). Pairing ang grouping are different activities. Similarly, a Sub is “bonded” to a “controlling” speaker such as a single Five or stereo-paired Ones. Similarly, surrounds are bonded to the Arc or Beam in a home theatre arrangement.
 

Whether a single speaker or “set” of multiple speakers, once set up the roomname is used to control all in that room set as a single entity, but you can (whether or not you’ve run Trueplay) then adjust Sub volume separately from the speaker(s) it’s bonded to. 

Many people do not seem to find this page, that explains grouping and ungrouping rooms: https://support.sonos.com/en-us/article/group-and-ungroup-rooms Maybe Sonos could do something about this. More importantly: to many people the fault code when trying to make named groups when you only have two “rooms” is unclear. The option should preferably not appear when you only have two rooms, but at least its should point to the right way to group two rooms, which it does not at the moment. It just says you can’t make a named group, but does not mention the right option.

See the screenprint from my app for the right button for grouping even if you only have two rooms:

Thank you, I agree it would be helpful for Sonos to point users in the correct direction instead of just greying out the group option with no explanation that going to another part of the app solves the problem.  It says 3 or more devices are necessary to use groups.   It should point is to Airplay instead

Those are just group presets.  All they do is make a macro which checks/unchecks the right rooms for the group, saving you clicks.  The reason it's grayed out for two rooms is because making a preset out of two rooms doesn't save you any clicks.

Also, this has nothing to do with Airplay.  You can group two rooms easily without Airplay.

@Sonata5 

And creating a group of rooms via airplay is a completely different thing. This function creates groups using the airplay protocol. Sonos uses its own protocol to do this. 

This response proves my point though.  I am sure you are trying to help but none of the grouping/pairing instruction apply to the topic I am raising.   Yet that is the same response we get in every forum post.  The conversation always goes in circles about setting up pairs for a home theater or setting up 3+ device/room groups instead of answering the 2 device question correctly and concisely.  Experienced users seem very focused on us learning correct terms for a 3+ system without offering an alternative word we should use instead. Is “syncing” the correct word approved by Sonos?  I don’t know because they haven’t provided that info in any posts I read.  

People like me are not going to run to the store to purchase more devices in order to follow the official Sonos branded grouping/pairing/room instructions that are always picked as Top Answer.  We also don’t know how to ask the question any differently than we have been. We use the words “group” and “pair” because those are basic English words that are normally used in the scenario we are trying to set up, regardless of brand, so the answer to our question shouldn’t be dependent on knowing the Sonos redefinitions right off the bat.  It’s frustrating that arguments over basic English words become the focus instead of fixing a problem that many new users are apparently experiencing when using Sonos for the first time. 
 

We are not asking to play two speakers in stereo in the same room.  We are not asking how to set up subs in a home theater.  We are asking how to get 2 speaker devices playing simultaneously (not in left/right speaker mode) in two different locations of the house (“rooms” or “portable”) in order to hear the same music playing when we move throughout the house.  Think whole house sound system.  But we can’t figure it out when the Sonos app does not clearly explain how to do that.  We naturally gravitate toward setting up a “group” or “pair” for our 2 speaker household system via the app.  We are frustrated when it is greyed out and it implies we need to purchase a 3rd device in order to create the whole house system we want.  When we go to the forums for help, we get told we are asking the question wrong, using wrong terminology, setting up bad sound systems or pointed toward the official group/pair instructions we already looked at.  
 

I like 106rallye’s answer.  When the group option in the app is greyed out, a popup says “this feature is available for 3 or more rooms.”  Sonos should add “when group option is disabled, select multiple devices in Airplay.”  

I don’t know why. You can still group two rooms in the Sonos, it’s only the shortcut for three or more isn’t available. In fact, if you send an AirPlay stream to multiple rooms, you’re increasing the bandwidth from your Apple device in order to stream to each speaker. So, double for two rooms, triple for three, etc. 

Is that decision to not show the grouping feature unless there’s three rooms confusing? In my opinion, yes, but someone at Sonos made the choice, probably for simplicity. Less or equal button clicks. I get that. But this thread encourages the misunderstanding that you can’t group two rooms using the Sonos controller. You can. 

No, they shouldn't, because that's not how you group when you only have two rooms.  Here's how you group any rooms you have:

In my experience the Sonos group is much more stable than an Airplay group, probably because (if I understand it right) Airplay relies on your phone for connections), instead of the direct internet internet connection to the music service the Sonos devices use. So my advice would be to group using the Sonos app.

Wow; I thought it would help you, and anyone reading or adding to this thread, if we all used common terminology to avoid confusion. I even tried to explain where the grouping button was, though @106rallye explained it better - with an image too.

It would seem that you didn’t follow my suggestion, or you would have seen the “list of rooms available to group” (just 2, in your current setup) and you should have discovered that it’s possible to group 2 rooms in a 2-room setup.

You complain “Experienced users seem very focused on us learning correct terms” and don’t comprehend the benefit of using common terminology. “Grouping” can refer to a system with 2 rooms or 22 rooms, and is the correct term to use. Similarly “pairing” has a specific Sonos meaning. You say you want to “pair” 2 rooms. In Sonos-speak, you need to “group” those 2 rooms. And, as said already by me and several other contributors, you can indeed group both rooms in a two-room setup. 

That said, I’ll now bow out of future contributions on this topic; I hope the advice that’s been offered by others here has helped you achieve your goal of playing the same music to both rooms in your home.

I don’t follow here. Having a two-room preset for both rooms is exactly what I am looking for, and absolutely would save me clicks. 

If I want to play kitchen → tap kitchen (1 click) 

If I want to play TV room → Tap ‘tv room” (1 click) 

If I want to play both→ Tab ‘tv room’, then tap rectangle thingy, then tap “kitchen”, then tap “Done” (4 clicks) 

If there was a way to save both rooms as a grouping, then I could play from that grouping in one click, which is what I’m looking for. 

@dval29 

Please think about it a second time. How should it be done with just one click?

Shortcuts for all different 2 room configs all over the screen…?

The way it’s done currently imo is quite good and simple and number of clicks is exactly the same for two rooms or selecting a shortcut. 
 

As I said elsewhere, if only one group is possible (when owning two speakers) the square grouping icon could be made two be a “group both speakers” in one press.

Yes, of course that would be nice and some kind of intelligent functionality option. But as far as I know that’s not what Sonos likes to be philosophy of their ui design. And as part of that I suppose an icon always has to have the same function. 

But that’s not how it works, the named groups aren’t accessible until you reach the grouping screen.  Right now for named groups (starting from the room that’s playing), you press the Group icon (One click), you press the name of the group at the top of the Group screen (Two clicks) you press Done (Three clicks).  For a two room group, You press the Group icon (One click), you press the check mark on the other room (Two clicks) you press Done (Three clicks).

Perhaps since I’m new (and am locked out of “grouping” ability), I am misunderstanding what grouping does. 

I would think it allows you to name “rooms” that are groups of speakers. Thus, when selecting a room, I could select “Kitchen” or “TV Room” or “Downstairs” or whatever groupings I created. This would acheive all the goals of simple, one-click listnening and would not create “shortcuts all over the screen” beyond just the standard list of rooms. 

No, that is not how it works.  Named group shortcuts are just macros that click the boxes next to the rooms automatically.  The rest of the grouping procedure is exactly the same. 

Ah, thanks for this. By dint of being new (and locked out of grouping functionality because of having only 2 roomns), I didn’t realize this. 

I assumed that grouping would allow you to name new “rooms” in the configuration you want. So I would have 3 rooms displayed: “Kitchen” “TV Room” and “Downstairs” where “Downstairs” woudl be a configured grouping of both kitchen and TV. 

This seems way more intuitive and sensical to me, but perhaps the downside is people with many sonos rooms could have too many configs? But overall would far prefer this option myself. 

But you’re not locked out of grouping at all. You can still group the two rooms together. 

Hmm. It seems like we are talking past each other here. 
 

My desire and expectation would be that I can name and save a group of speakers in a way that I can select them easily and automatically, the way I did for “kitchen.” 
 

Ideally, I would create a  virtual “room” called “all Sonos speakers” and assign all my speakers to that virtual “room.” Is that possible? Or can you only assign each speaker to one room max?

This thread is about the impossibility to form named groups if you only own two speakers. Because only one group is possible if this is the case, Sonos deems it unnecessary for you to make a named group.

I do not know if your envisioning a Sonos set up with only two rooms or a set up with more rooms, in the last case the problem does not arise. You also seem to confuse “rooms” and named “groups” in you post - “rooms” are speakers or designated (stereo or surround) se5s of speakers, “groups” are two or more room put together to play the same source.