Just checked again after update, still not Christmas....

Obi Wan went undercover assuming the identity of Rako Hardeen for one mission. He NEVER WAS an actual bounty hunter, he merely impersonated one for a brief time. Assajj Ventress fully became a legitimate bounty hunter after Dooku cast her out. The last two seasons of Clone Wars, she goes on several missions as a bounty hunter, and stayed a bounty hunter for the rest of her life. (as far as we know anyway, according to canon) Assajj Ventress SHOULD get a bounty hunter tag as she is one, more than anything else. She's more of a bounty hunter than a Sith, that's for sure. She's also more of a bounty hunter than she is a Separatist, although the Separatist tag is understandable as she was a Separatist for a fair amount of time.