Here's the answer to ON BASS chords. This answer came from a Yamaha rep.
--------------------------------------------
They will recognize 9ths, 11ths and 13ths and on bass chords. But the fun really begins when you combine the two and have two arp recognition windows.

The you cna do things that no arranger can do like play a C6 bass line over a series of chords in the right hand that moves down chromatically from E flat major 7, to D major 7 to C Major 7
--------------------------------------------

Squeak