"I see them as separate. Bondage does not imply "torture" and some players enjoy the tying up part but don't want pain -- at least intentional pain."

I agree CBB doesn't usually involve any significant amount of pain. I think for me the sensation serves as a steady reminder of what could be to come. It certainly helps me get into the right head space for the D/s aspects of a session.

"I don't specifically put "CBB" and "CBT" under my interests as a kind of legal risk reduction but enjoy both."

Interesting comment. Do you live in a jurisdiction where you have to be particularly careful to minimize potential legal jeopardy or is this type of play always something of a grey area in the US?