Yes, if you have a new Apple TV (£99) you can connect that to your AV receiver, use it to stream iTunes from your iPhone and control playback through Apple AirPlay on the phone. Or you can use an Apple AirPort Express.
PC/iTines to HiFi/AV is beeen discussed in another thread at the moment you may find some usefull info - http://community.whathifi.com/forums/t/542530.aspx