Welcome to the forum! Congrats on the new baby, btw.
I like the fireplace...but, yeah, that protruding wall is a bit of pain, isn't it?
I take it that moving the TV out to the flat wall next to it won't work?
Anyway, there are a number of different options out there, and I don't have the answer - but I figured that I'd welcome you and bump this thread for the other folks here to chime in.
For bluetooth (or WiFi), you could get that built into the speakers, or get a relatively inexpensive media streamer to handle that part of it. For example, a number of blu-ray players these days will also play music streamed wirelessly, as can standalone media streamers. Do you already have something like that?