There was no continuity to the Bantam novels, except between the two The _____ of the Phoenix
novels by Marshak & Culbreath. Occasionally a couple of novels by the same author might have a supporting character or two in common; for instance, Kathleen Sky's two novels both feature Ruth Rigel, the Enterprise
's veterinarian (yes, really).
In all, Bantam did 13 original novels and two anthologies, along with the 12 Blish episode-adaptation collections and J. A. Lawrence's Mudd's Angels
(combining adaptations of the two Harry Mudd episodes with an original Mudd story that's incredibly bad and bizarre).
Are they worth any money? Maybe a little bit of trade-in credit at a used-book store. They're not that hard to find, and have been reprinted and re-released multiple times.