Hey philipt42 - raopx works awesome! Instructions are easy and along with Soundflower, it streams great to my Airport and therefore my stereo. I also use wireless speakers thru my headphone jack on the receiver - it seems it is always an either/or situation with regard to wireless/remote speakers in either the headphone jack on the computer or thru the jack on the receiver.
I am now very happy streaming Pandora all over the house, with my iPhone in my pocket and not as the streaming device thru the stereo - thanks Sfhawk for the recommend!
~K