I have a 2012 Legacy with a Razr M, and also have a BT headset which works perfectly. I have given up on using the Subaru Bluetooth connection entirely for several reasons.
1) the implementation is horrible - VERY unintuitive setup and device management, poor functionality (who wants an address book in their car? / unable to use phone address book),
2) changing any settings on the subaru-phone BT connection (ex. disconnecting phone audio) resulted in problems with my bluetooth headset connecting to the phone.
3) even if I didn't change anything on the setup (turning on/off audio or phone connection to the car), my phone would lose connectivity to the BT headset while in the car. I don't know if this is the fault of the phone, the car or the headset, but having them both paired means that the headset is completely unreliable, which I can't have.
I finally determined that the best solution was to turn disconnect the Subaru BT system completely and use a wired connection to the audio to prevent me having to constantly re-establish the bluetooth to my headset (Motorola H730).
If Subaru implemented a system where the on-car system had the option of acting like a dumb VT headset and used voice commands from the phone we'd be all set.....
Very disappointing product.
I saw this thread after looking for answers as I have the same issue as well. My GF has a 2013 Subaru Legacy and I was trying to pair out phones (HTC One) to the car. I connects fine, we can make calls just fine and hear audio notification as well. What it doesn't do is stream audio from 3rd party apps like Pandora or Spotify. It will play songs through the built in app just fine. But if you have zero songs or would rather have stuff streamed through it then it should work.
Not sure who is at fault as I use a pair of bluetooth headphones everyday to stream music and that works just fine as well as a bluetooth receiver that works fine streaming everything.
I have yet to try the iphone as I have one as well I could try out. Just seems weird that it doesn't go through 3rd party apps.