So after experimenting with a HC-05 module... I have learnt how to connect to it, use puTTy on PC, and talk via Blueterm on Android.
Plenty of searching for answers shows that .. No, the BT does NOT support 8192baud.
The only solution is to make a baud rate converter. I am looking at a few options since my coding skills are pretty weak.
One is a software serial converter possibly using a ATtiny85, it has dual timers, and there is existing code I can modify for a single bi-directional lane.
There is sufficient pins to support another lane.
The other is a dual uart ATmega.. either way, a ring buffer will be required... its overkill, but cheap, and can do two channels. Probably easier.
I've ordered one of each, I plan on doing some other Arduino projects anyway so I'm happy to muck around.

Cheers!