no
You've misread what you've found, or at least greatly overestimated what it's capable of.
For both HomePod and sonos, any "linking up" is done in the initial setup. and once it's set, it typically doesn't change.
In sonos, if you add two surrounds to the beam, as far as sonos control is concerned those 3 speakers are now one thing. In the sonos app, where you select rooms, you'll only have 1 entry for the entire surround group.
there is no surround with HomePod, Stereo pairs work OK, but is limited, (you can't send full system audio from your Mac to stereo HomePods. I believe currently from a Mac, you can only send to a stereo pair from the music app)
airplay is limited to stereo only. Although in some cases you might be able to get surround.
For example, if you airplay from appleTV+ on your phone to an appleTV, it just tells the appleTV the location of a stream to play from the internet, so it plays back in full quality, but it's not really true airplay.
You can set a stereo pair of HomePods as the front speakers for an appleTV, but how well it will work depends on which apps you use, and how good your wifi is. The direct connection via HDMI is much more stable.
Surround grouping works only for sonos speakers, if you want the rear channels, you must get sonos. You can get the cheaper One SLs without the microphone, since the microphone is disabled when used as surrounds anyway.
you can also get the speakers from Ikea, they sound good, and will be fine for surrounds. and only $99
Things can be airplay senders or receivers. most are one or the other, some are both.
- HomePods and appleTVs are the only "both"
- phones, iPads, Mac, are just senders
- There are third party apps for Mac or iPhone that can turn them into receivers.
- airport expresses are just receivers
- most third party products like speakers (sonos), and TVs are just receivers.
so you can send audio from the HomePod to the beam, but not the other way around.
The only way the 2 systems play together currently, is ...
- you can play something from Apple Music on your HomePod, and then send that stereo audio to the beam. (supposedly other music streaming services are coming soon)
- you can airplay stereo audio from your phone or Mac to both the HomePod and the beam simultaneously.
- From the aTV, you can airplay to the homepods, and HDMI to the beam, but the HomePods will only be the front channels.
If you add more sonos speakers in other rooms, once the TV sound is in one speaker, it's available to all other sonos speakers in your system.
You can group sonos speakers in the rest of your house with the Beam, and they will all play in sync.
I have one HomePod, bought when I had a few airplay speakers scattered around.
I've since changed to sonos.
I keep the HomePod only because I have a lot of homekit stuff, and it's nice to have siri hear me. I rarely ever play music on it.
If I can get a decent price to resell it, I'll probably switch to a mini.
I normally just play Spotify using the sonos app