WINS, even when owned by Infinity/CBS, was never a CBS affiliate. This was by design; a way to prevent brand dilution of both WINS and WCBS. Infinty/CBS understood both stations had their rabidly devoted fans and airing any kind of CBS News mention on WINS would be confusing to listeners.
WBZ was a different story. It added CBS affiliation alongside it's ABC affiliation. Boston didn't have the NYC dynamic of WINS/WCBS. Few cities really do.
I dunno about now, in the Entercom era, what WINS' affiliation deals area. But back then, CBS wasn't one of them.
Yeah, you're right about that one. Now that I think about it, most of the actualities I heard on WINS back then came from AP. The Group W newsers generally didn't take TOH during the wheel because, well, they were in the news wheel.