I don't believe you can do this if you DON'T have idrive. I have an '11 335i with no idrive/navi, post Sept build, and have not been able to do BT streaming. I have an Android phone, but don't think those with iPhone's are able to do either. The BMW site shows you cannot stream without idrive. I have upgraded HK sound too, but doesn't seem to matter.
That said, I did try an iPhone 4S thru USB and got that to work...sounds so much better than Aux.
Guess I might have to get an iPhone...I spend a lot of time in the car and for the sound quality difference, it might be worth it. Good Luck!