Not sure what you're doing wrong. I simply connected the phone to the bluetooth system and then selected bluetooth from the menu on the touchscreen! This is using an iphone although i can't see why there would be a problem using the s2?
mine works ok with (via bt) Windows phone 8(Nokia lumia 920) the only thing that disturbs me is that its a delay on the stream.
you can for example watch youtube and hear almost instant that the audio are delayed with 1sec...
gonna check for firmware update on my first service.
Un plug your phone from the charger and then try. Connect device to touch screen, then start playing music on your phone and select Blue tooth source. It should be then playing.
Also try going into connection settings, select the phone connection and check that the box for audio streaming is ticked. If this is not selected then It will not allow you to play music bu the will allow you to make phone calls