Not sure I understand. What speakers do you have? 

TV input from a home theater room will always have a slight delay of at least 75 ms on all grouped rooms, but there is certainly the ability in the controller to set ‘include grouped rooms’ at any playback point, and unless you turn off that feature, your rooms should always be grouped when you start playback in your ‘home theater’ room. 

If you are using a Sonos HT device such as Arc, Beam etc. then group it with all your other Sonos ‘rooms’ and navigate to ‘Settings/System/gHome Theatre Room Name]’ in the Sonos App and switch off ‘Ungroup on Autoplay’ …and your devices/rooms will then all stay grouped when playing either music, or TV, audio.

Thank you! Just what I was looking for.