According to Dr. Hale's book Mothers Milk and Medications Wellbutrin is classified as an "L3" which is considered safe for breastfeeding. The only possible issue mothers face ( and this is debatable according to Dr. Hale himself but he has to put it out there ) is decreased supply. So, if you're trying to relactate keep this in mind and maybe bulk up on foods which are lactation friendly. I don't think you should have any issue with relactating since it appears that you've only been a couple of months without pumping.
I breastfed on Wellbutrin (as well as Lamictal simultaniously) with no problems and I am confident about returning to it when my new bean arrives since like you it is the only thing that works for my condition.
Good luck mama!!
PS here is a link to the part of Dr. Hale's forum which discusses anti depressant meds and lactation. It's only open to questions from Health care providers but anyone can read. Great resource.
http://66.230.33.248/discus/messages...tml?1204291787