I have a Bose Lifestyles 5.1 surround system. Brghthouse upgraded the firmware on their DVR's and now all I get is PCM, no more Surround Sound 5.1. Does Bose recognize the output of your DVR's as Surround Sound 5.1?
I see no reason why the output from FiOS STB's would not be recognized as the format that is being sent through for the channel. I have not tested this exact surround system tho. Maybe there are others here who have a Bose surround system that is in use with a FiOS STB.