If you mean through the Connected Drive App, it will not work. It's either one or the other. If you select Pandora on your phone or iPod, you should see the Pandora icon in BMW Apps but that's it. Can have both running at once. Same with MOGG, Stitcher, etc (any third party app not included in the Connected Drive App lineup).
Not a fan of this as you have to get to your external device everytime you want to switch between third party apps.