To really make use of the RBI, your best bet is to get an A/B box so you can switch between it and the pre amp on the Ampeg. Otherwise, you're running a full pre-amp section through a second full pre-amp section, and things get get pretty ugly pretty quick. If you have the manual, the hookup diagrams on page 13 will lay it out for you. Just in case you don't, here it is. http://www.tech21nyc.com/support/man...amp/RBI-OM.pdf
Is the BBE the rack-mount version? If it is then it's the last thing in line before the power amp. If it's the pedal version, I'd suggest looking into the rack-mount. Knowing what the BBE process is, I've never understood the pedal version myself. Way to far up the chain to do it's job correctly.
Seeing what you've spent on gear already, it's worth looking into both a good foot-switchable A/B box and the rack-mounted BBE and doing it right.
Wireless > Tuner > RBI,Ampeg pre-amp,A/B box set up > BBE (rack-mount!) > Power amp > Cabs