@gmacsolo I haven't seen the TBP12G available for awhile, but it looks like it's in stock now: https://shop.line6.com/accessories/wireless-accessories/relay-g50-g90-bodypack-tbp12.html
But, since it is very difficult to get ahold of, the original question, is the V75 version totally compatible with the G50/G90 or are there any drawbacks?
This page indicates that the V75 bodypack is compatible with the G90 and G50.
https://shop.line6.com/accessories/wireless-accessories/transmitter-for-v75-wireless.html