setting up AirPlay for AV receiver?

Have Yamaha Adventage receiver RX-A2010 with airplay. I have Airport Extreme in the next room and Airport Express behind the receiver to extend the wireless.

NOTE: In my new home, I don't think I need the Airport Express anymore, which might help if I remove it.

I am not sure what receiver settings need to be for AirPlay to work. I checked the Yamaha and it show some MAC address but were empty. I don't know if I have to set the Yamaha with a Mac address or not. (If I do pls let me know and I will contact Yamaha for help).

When I select AirPlay from my iPad, it shows my iPad and the Airport Express. As I said don't know what audio settings the Yamaha needs to be set on or if that gets connected once I set up a Mac address for the Yamaha. The Yamaha has to be set to something to work i.e. AV1, AVsomething, tuner etc.

Thanks,

Don