This thread should be in the help thread. but anyway:
In the Trinity Global Mode, Page 1 make sure that the Trinity is in the Post KBD mode instead of Pre TG. Select Global midi channel to 16 or simply adjust the receive channel of the Sonic Cell to whatever Global Midi Channel selected in the Trinity. In page 2 click enable program/bank change, as well as control change and other necessary preferences.
I never bother with the MSB (as bank number in mm) or LSB (bb) in the Trinity's term of Bank change parameter.
For more detail information, the manual can be downloaded here
, just in case. The combination of both is very nice, reminded me of my early set up consisting just the Trinity Pro and the JV-1080. What I did is just turn off the program/bank change and edit the JV-1080 directly and save the setting in one of the performance patches. Not sure about the Sonic Cell structure though, supposed to be easier to work with rather than the older JV module.