I agree with the above poster. Bi-amping serves no purpose whatsoever. But to answer your question, no you cannot with the unit you are considering. It a 2 channel amp only and has no unused internal amps to use like an AVR. Even with an AVR, bi-amping by using the unused channels brings no benefit.
Just hook up your B&W's to the Marantz normally and enjoy the music!
Marantz PM15S2 LE, Arcam FMJ CD-17, VPI Traveler V2 with an Ortofon Rondo Blue, Technics SL-1400 with an Audio Technica AT-14sa, Simaudio Moon 110LP, Pro-ject Phono Box S, Pioneer Elite VSX-52, Pioneer Elite BDP-52FD, Dynaudio Focus 260's, Vienna Acoustics Theatro Grand, Wharfedale Diamond 9.2s, REL T-1 & Panasonic TC-P54S1