If you mean it's a reputable massage spa like a non-sexual one, I'd be very surprised if it was his tongue, but then again, his hands shouldn't be inside your buttocks, either, during a non-sexual massage.
In any case, there is no risk from hands at all.
If it was his tongue, how long do you think that lasted? It sounds like a couple of seconds, maybe? If that's true, that's not long enough to transmit anything.
Rimming carries a risk for gonorrhea, syphilis and genital herpes type 1 if it lasts long enough to transmit anything. There's no real scientific time for how long that takes, but we know that a quick kiss on the lips isn't likely to transmit oral herpes, but a longer one with friction is more likely.
I wouldn't worry at all if I were you.