Not sure what you will get via wireless iPhone playback for that money, if anything, sorry.
The Denon (H/K - same producer) AVR-1912 has something called Airplay, and its little brother the 1612 might also, but they are above your budget.
@ssddx is totally correct in that Onkyo do a good budget receiver, but again I'm not sure you will get an old model TX-SR308 or current model 309 for $200-300. In Australia they are $400-500 new.
I'd try pioneer as I think they do budget receivers. If I were you $100 extra would give you so many more options. You're really limited in that price range and a small amount more will open up heaps more options.
Or go second hand, you'll save about 20-40% on last years model.