Is the Roam powered on? Also try rebooting your router, iPhone, and Macbook.

Roam is definitely on, and can be seen from within the S2 app.

I can also airplay to Office and pair it with Roam to get audio to play from it, but cannot see/choose Roam directly.

Not sure why it was happening, but I reset the Roam using the official instructions and set it up as a new speaker.  I can now see Roam in AirPlay as before. 

I had the same problem.. Then I realised my Iphone was connected to the 5ghz network and Sonos uses the 2.4ghz.  Had to reconnect Iphone to 2.4ghz network and all speakers appeared .

For Airplay to see the speakers you have to ensure your phone is on the 2.4ghz..

If what I have stated is wrong then Im sure someone will correct me but as I say it worked for me.

Hope that helps

That sounds a lot like you were/are experiencing the 

issue, @Northbriton. In general, most routers shouldn’t have an issue with seeing / AirPlaying from a device that’s on 5Ghz when the Sonos is on 2.4Ghz. 

Yes .. saw that issue. However I am on Virgin and that problem is not the case here

I’m also having the same issues with Roam.

It sometimes connect over AirPlay from iPhone, and then after few hours/minutes it stops playing and I cannot connect anymore.

Same problem here - in fact I was listening to something on Airplay and it just went dead. It does not show up as an airplay available device.

It DOES, however, show up as a Sonos device.

So it cannot be matter of it being on different router bands etc.