Connect a Sonos home theater device like an Arc, Beam, or Ray to the TV. Then group the Sonos home theater device with your other Sonos speakers throughout your house by following the instructions in this article:

https://support.sonos.com/en-us/article/group-and-ungroup-rooms

NOTE: When playing TV audio, you may experience a slight delay from the grouped speakers. Streaming music will be in sync though.

But, you’ll not be aware of it if you’re listening in a different room. It’s only apparent if you are in the very narrow zone where you can hear both the speaker connected to the tv and a different room speaker. 

thanks a lot, very interesting

To be precise : if i have a SONOS BEAM GEN 2 and two sonos ERA 100 as satellite in my living room, and some other ERA 100 elsewhere in the house, SONOS application will “treat” the two satellites ERA 100 differently than the others ERA 100? as some are part of the home theater and some are stand alone speakers

Correct.  The Beam and surrounds will be one room.  The other speakers will be their own room(s).  You can group rooms together using the Group feature and they will all play the same source.  

Group and ungroup rooms

Thank you again for your help

one last question : how does the sound go from the tv to the satellite speakers and the other speakers ?

tv → HDMI cable -> soundbar

soundbar -> bluetooth → satellite 

soundbar → wifi → other speakers

?

The soundbar creates a dedicated 5Ghz wifi link to the surrounds. The soundbar and any other rooms/speakers will be on your wifi network. 

TV → HDMI cable -> soundbar

soundbar → 5Ghz Ad-hoc wireless connection → ’bonded’ surround speakers

soundbar → 2.4Ghz WiFi or Wired LAN connection → to ‘grouped’ speakers in other ‘rooms’

The difference btw 5ghz and 2,4ghz explains the sound latence (Delay)btw the suround speakers and the others ?

No. 
 

The delay is needed for synchronised multi-room streamed music, which was what Sonos first offered to their customers. The same delay exists if you use a line-in aux input on a speaker with that input option. Without any video, you’re not aware of the delay as there’s nothing to sync it with. When Sonos introduced home theatre products, they had to minimise the delay as much as possible for the speakers attached to the tv, but the delay still exists when playing out to other rooms/speakers.
The surrounds bonded to the tv soundbar uses 5Ghz to minimise surround effects as much as possible.

The delay to other rooms will still be present whether the wifi is on 2.4ghz or 5Ghz wifi.  

You could also say “yes”. The 5Ghz link is faster and it is also direct, so less buffering is needed.

@alexis0391,
Just to add there are some tools in the Sonos App that you can perhaps consider in this context too..

• ‘TV Dialog Sync’ - slider control - allows the user to adjust/buffer the TV-audio on the HT room and its bonded surrounds, to try to bring the playing TV-audio in sync with the ‘grouped’ rooms. That of course has its disadvantages too with the video on screen, such as lip-sync, but is often fine when playing from TV music-only Apps and the display is not critical to the listening experience.
• ’Group Audio Delay’ - a low/medium/high/max setting - allows for greater delay/audio-buffer of the TV-audio to all grouped rooms, which is useful for coping with the higher demands of TV-audio across a wired/wireless network to multiple rooms and can help prevent audio dropouts to those rooms. The delay is often irrelevant if the ‘grouped’ devices are located in an entirely different physical room with walls in-between etc. It helps to ensure reliable TV-audio playback on some problematic, or poorly implemented, networks that maybe suffering from wireless interference etc.