...I'm making this more complicated than it should be...
Bouncing and flash rotation are not "mutually exclusive tactics." Flash sits on rotation bracket just like it would be in hotshoe. When you are in portrait orientation, it rotates, staying in same orientation. Go play with one at a shop.
I've been plenty times with flash in hotshoe, camera held portrait orientation, flash head rotated about 80 degrees-right, bouncing off ceiling. Bouncing depends on distance and color of bounce surface and exposure goal of photo.
Plenty good tutorials by Curtis here on POTN and other places about bouncing flash.
BTW, While a flash bracket can be a be honkin rig, one side benefit is when working big crowded events (like conferences), persons see you, know you're a photog there to make the shot, and they move the hell out of the way, and don't interfere with getting the photo and doing the job!
Jack