Stalker by Clarissa Lake

Stalker Knight is one of six Cyborg Marine Rangers who have returned to Earth to bring law and order back to North America West after an interstellar war left Earth in ruins. Each of the team members hopes to find their one genetic mate.
Stalker finds his mate when he pulls the pilot from a plane shot down before it explodes. Neely Albert, a former prostitute turned smuggler, is not impressed when Stalker announces that she is his genetic mate. However, her smuggling days are over with the loss of her flyer.
Neely is worried that the overlord will make her pay for the weapons. The big cyborg ranger talks her into going to California to help him with reconnaissance in L.A. in preparation for rebuilding. Neely sees it as her way out, but she also can’t deny her intense attraction to Stalker.
Once Neely agrees to go west with him, Stalker can just let nature take its course. He is pleasantly surprised by how capable she is of helping him.