In the comics, Buffy's romantic storyline didn't culminate with Spike. There were various plot developments and other characters involved in her relationships.
Buffy's relationship with Spike in the comics varies. Sometimes they have significant interactions and may even be romantically involved, but it's not a constant throughout all the comic series.
It varies from comic to comic. Sometimes they have a romantic connection, while in others, their relationship is more complicated or not existent at all.