OK, so as a follow-up, I was able to use Brian's reaper to access my bike using BlueTerm on Android.
It appears as a serial device, so it would appear to be talking to
the USB+ and USB- per Burton's diagram, not the CANBUS (which
is a packetized protocol, and shows up as a network device, like
ethernet).
After pressing ENTER a couple of times, I get the MBB> prompt.
help gives you a list of commands, and status gives you a bunch
of values, including battery voltage if you are interested in that.
Terry claims the battery voltage is a much better predictor of the
remaining range than the reported SoC for those of use with 2014
running-out-of-power early issues (mine is typically 6%, but I've
had loss of thrust and quick-drop as high as 14% riding faster on
a warm day).
And having something working on the OBD-II connector, I can confirm
it's not like the standard OBD-II, in fact an OBD-II Y-cable made for
cars doesn't work (apparently they didn't wire up the "unused" pins
that zero uses.)