Geez! OK. I understand a little more now. So the 2 centers are going to be wired no matter what it looks like. So lets also forget about the sub and think about the side speakers. So you have six of those. From a laptop, using itunes (mac or pc), you are able to airplay to multiple receivers/apple tv. Your 6 speakers in this case. All of those "speakers" are 5 speaker, stereo dock units. While you can stream airplay to all of them you'd be streaming the same stereo signal to all of them. Defeats the purpose of the surround entirely. You cant separate the channels and say Airplay, send front left to this one, and right middle to this one.
I don't see how it can work if it isn't wired? Not to mention the speakers themselves have to have power so now you have to plug them into ac and run a speaker wire to them. Maybe they have batteries, I don't know. I think you better check out some of the theater sound forums. I realize it's outside but the principals are the same.
PS - Your wife is going to kill you