The Chimes at Midnight
in Myriad Universes: Echoes and Refractions
is a followup to the alternate timeline from "Yesteryear," exploring how the events of The Wrath of Khan
and its sequels might have unfolded in a world without Spock (although how they managed to save Earth from V'Ger without Spock around is never explained).
A younger Carter Winston ("The Survivor") appears in The Final Reflection
by John M. Ford (although I'm not sure the chronology works, because he would've had to be a few decades older than he looked in the episode).
Howard Weinstein's first Trek novel The Covenant of the Crown
reuses choriocytosis, the disease from his TAS episode "The Pirates of Orion," though that's a tenuous link.
The Delta Triangle from "The Time Trap" is revisited in SCE: Where Time Stands Still
by Dayton Ward and Kevin Dilmore, and briefly referenced in DTI: Forgotten History
by yours truly.
also fleshes out the background of "Yesteryear," gives a supporting role to TAS engineer Gabler, and makes some other TAS references.
Excelsior: Forged in Fire
by Michael A. Martin & Andy Mangels has some flashback chapters revealing what happened to Koloth after "More Tribbles, More Troubles."