Hi.  I think you mean “portable” rather than “wireless”, as many of Sonos’ speakers can be used as wireless surrounds, and indeed this is the norm.

I can see why you would find this a desirable feature and I cannot answer for Sonos.  My best guess is that different speakers are aimed at different use cases.  Portable speakers - the clue is in the name - are meant to be ‘pick up and go’.  HT systems are meant to be semi-permanent, with the surrounds “bonded” to the soundbar and almost becoming part of it.  Portable speakers will run out of battery, as some users inevitably forget to charge them.  That will always be when you have friends round for a movie night.  I suspect Sonos would want to see the right speaker for the job, rather than have lots of sub-optimal experiences of the system.

There may be other, more technical reasons not to allow this.  But portable speakers don’t seem a natural fit as surrounds to me, despite the scenario of no convenient power sockets.

And for the avoidance of doubt, there are no end of technical reasons why Sonos surrounds oould not possibly worrk with a JBL soundbar.

I agree with what John stated, but have to admit that the Sonos home theatre seems to do ‘ok’ when the mains powered surround speakers are unplugged.  By that I mean that the soundbar and sub will keep playing, and once the surround speakers are plugged in and booted up, they will play the rear surround audio without fuss.  It seems reasonable that portable speakers could do the same?  

I have heard Sonos reps say that part of the reason is that the Move and Roam are more designed to fill a room with audio and thus aren’t built to be good surround speakers.  There is also the probably that it will be difficult to properly tune the surround speakers if the speakers are placed in different positions each time, left/right speakers are switched, or placed in a different room of the house.  Maybe more importantly, if portable speakers were used as surrounds, they would lose the ability to be used as their own separate room while on wifi.  You wouldn’t be able to take them to the backyard or any place with wifi.  You would really only be able to use them as stand alone bluetooth speakers when not used as surrounds, and I suspect that’s a little less than what people want?

I think you misunderstand me; I’m not saying I want to use my Sonos wireless speakers as rear surrounds with the JBL system; that already works perfectly as it is.

The point I’m making is why doesn’t Sonos allow you to use speakers like the Roam as the rear speakers in an all-Sonos surround system? It would be a fantastic USP to be able to take your little travel speakers, or your kitchen and bathroom speakers, in to the front room, click a few buttons on the app and there you have it, a Dolby Atmos rig, using a Sonos woofer, sound bar and front speakers...

Hi, yes, you’re probably right, maybe ‘portable’ is the term I should have uses.

To expand on how the JBL system works, the rear speakers attach to the sides of the soundbar magnetically, which is where you store them and where they charge;  it switches from a simple soundbar surround system to a Dolby Atmos system when the rears are pulled off the main bar and then positioned as surround speakers.

https://uk.jbl.com/outlet/JBL+BAR+9.1+TWS-.html

One thing I would say is that because of the nature of the way they snap back in to place on the main soundbar, to store them and also charge them, I have never had them run out of juice when I needed them. To my mind something like the Roam with the magnetic charger would be an equivalent - certainly the way I use them is they live on their charging stations, until I want to take them somewhere, either around the house or in the garden or out to the park etc. Surely the responsibility to have an optimal experience of anything rechargeable - a speaker, a lawnmower, a car - lies with the user, not the manufacturer; if I run out of battery in my car, I can hardly blame VW or wherever, because I forgot to charge it. And forgetting to charge the Roam before wanting to use them when out with friends in the park would provide a sub-optimal experience but I could hardly blame Sonos for that. 

Anyway, I take your points, I just think Sonos are missing a trick here; for me being able to group my Sonos travel speakers in to my Sonos home cinema set up would be a major selling point, especially as I wouldn’t need to then spend extra on having travel speakers AND rear speakers (yes, I realise this is one reason why Sonos might do things this way, to make you buy more from them, but this could back-fire, as I’m less likely to go with a Sonos surround system in the first place if I can’t use my Sonos portable speakers with it)