Do you have NAC? If so, I can imagine a very manual way where you create a location for each AP, then have a rule for each Apple TV (so each would be in its own end-system group) that allows access from that location, then another rule that denies access from any other AP.
Honestly though, look at hard-wiring your Apple TVs, we have more than 100 and wouldn't consider doing it any other way.
Another thought that came to mind is putting some metal next to the Apple TV in the direction of the AP in the next room, that might lower the signal enough to make it connect to the AP in its room.