Guild Hunter - Series by Nalini Singh

Angels in the world have little to do with heaven - instead, they are incredibly powerful and long-lived creatures who control the world. They also create and control vampires in exchange for a contract of servitude. 

Elena Deveraux is a bounty hunter who retrieves vampires when they break their contract. She gets in over her head when the Archangel Raphael hires her personally. 

Tags: angels, paranormal romance, vampires