Hi Nicole,
I was able to have some success with this and finally got my iPhone to pair as a BT audio device.
The key was pairing it as an audio device. Initially I had paired it as a phone only, so I was able to do hands free calling; but I also needed to register and pair it as a Bluetooth media/audio device to enable media (music/podcast/book on tape/etc.) playback through BT. I did this by doing the following steps touchscreen>setup>audio>bluetooth devices/pairing>register bluetooth device> I then followed the prompts on the NAV screen and paired it with my phone.
I hope this helps you!