I look forward to Luna6's update. In the meantime, investment professionals in the group will have already noticed Visa's disclosure that "[t]he selected rate may vary from the rate Visa receives."
I'd also have the same question on the ATM side were it not for the fact that, if memory serves, BofA charges me 3%; Chase 1%; and Citi 0% -- a separate topic from the Forex rate itself, obviously.