IIRC that label began appearing when M&S bought the company, and was used as recently as a few years ago (they may still be using it on some jacket for all I know).
I've never really considered the different "lines" of BB, but most of the jackets I've seen with that logo aren't anything spectacular as far as materials or construction.
During the M&S era they had some suits with a silver version of that logo, I'm not sure the exact equivalent but maybe golden fleece levels.
They also used the silver tag for their "digital tailoring" suits. I've seen a couple and they're nice, but they styling is a little off, two button, darted, shoulder-y, very un-BB-like. They also seemed to be made mostly of thinner worsted wools, and tend to get beat-up and shiny faster so buying used can be a problem.
If it fits and you like it and everything good find.