that Bose eq is going to kerfutz things up big time.
The problem you are going to have is that All speakers, not just the Bose speakers, will be getting the "benefit" of the Bose specific Equalizer. Now, this will be great for your Bose speakers since the speakers and eq were designed as a matching pair, but it won't be so great for the other, non-Bose speakers you are running.
Your best bet is to get a separate power amp, split the preamp/main amp, put in a pair of with a "Y" splitters, feed one side signal back into the Marantz to feed the non-Bose speakers directly from the Marantz, and the other leg to the Bose amp, then to the other power amp, and then to the Bose speakers.
that, and it will also alleviate the potential problems of overstressing that amp with the boost that eq will apply and/or running more than two pairs of speakers simultaneously. It would be a shame to smoke that nice receiver.