There are a number of concerns here.

Zones 2/3/4 do not have any DSP's to process Dolby Multi-Channel content. However, they most likely will process PCM two channel content and send that same signal to the remote zones.

Alternately, you can also connect either of the digital inputs (Fiber or Co-Ax) and or the analogue RCA's from each source device to accomplish the same thing.

Also keep in mind that surround processing creates a noticeable delay in the remote zones so you will need to play stereo or Game Mode in the Main Zone.

msm