No, it still requires an Arc with an HDMI-ARC connection to a TV set, which is connected to your Apple TV. 

I subscribe to Apple Music and Amazon and play Atmos from both via the Sonos S2 App.  Don’t have to go through ATV4K.

But not via Bluetooth, which was the question. The OP’s tracks are local, not on a service. 

Hi. I’ve got the same question. I’m a sound engineer and I produce Dolby Atmos mixes. I want to check them on my ERA 300. For the moment I don’t succeed to play the mp4 coming from Pro Tools with the Dolby Atmos Renderer for binaural QC with Apple Spatial Audio because I can’t load them on the cloud in Apple Music. And when I play it (the mp4) from the File folder of the IPhone with Airplay, it seems to play it in stereo.

I can’t either play my mixes from Logic Pro straightly through Airplay.

Maybe someone from Sonos could tell us what kind of file do the Sonos speakers need to play it in Atmos from our computers or IPhone and how to play it.

And to be totally clear, this is not the matter of playing Atmos files that are already in Apple Music, BUT to play Dolby Atmos files (or Spatial Audio) that are still in our computer at the production stage.

I think soudheals we got the same problem.

Cheers.

Yes I appreciate that.  Just trying to be helpful.

@RonanDemdel Yes, We do have the same problem.  You phrased the question much better than I did, thank you! If the Sonos speakers have a built-in “receiver”, there should be a way to do this but I cannot find any information online about it.

I think there may be two related questions:

What formats are supported by the device internally.

What formats are supported by the different inputs.

Corry P from Sonos answers there : 

Thank you, @RonanDemdel !