Typically speaking, the playbar/playbase/beam/sonos amp (sonos speaker) should connect to your TV/projector. Therefore, your TV/projector needs to have either a optical output or HDMI/ARC, with passthrough of dolby digital 5.1. We often see that projectors don't meet the requirement, in which case you can connect your sonos speaker directly to the Apple TV, if it's the only video source you intend to use.
All that said, I can't say I've seen a specific projector that I would recommend. It might be better to just find one that meets the video quality requirements you're looking for, and then just handle audio directly from the source (apple TV) to the sonos speaker.
As far as avoiding wiring between your projector area and where you want to place a sound bar, the best thing to do if possible would be to have wires behind the ceiling/walls. Of course that usually isn't practical. The other thing I've seen is to use wireless HDMI to send the audio/video from the projector area to the sound bar. You will likely then need a convertor to change from HDMI to optical audio into the soundbar. In general though, I'd say projector and soundbars don't mix well.
Danny