No native solution yet, but Mettle's Skybox can make 360 videos in AE. Some pretty nice results from it already on YouTube.
You're right, by the way. 360 videos are the only way companies can get people to interact with their ads on Facebook mobile and it really works if they have compelling content. I had a BUNCH of fun the other day with a surfing video a company put out on Facebook. It was just so cool to be able to look all around! I was swinging my phone this way and that and I watched it at least three times.
youtube / google has a special tool (software) to make it look proper 360 again. you probably already found it.
but i'm also eagerly awaiting good native 360 support (view, change angles, export) for premiere.