After we were done playing I tried speaking with him, and we found that neither of us knew enough of each others language to say more than "that was good...I had fun...let's do it again." Of course those are probably the key linguistic points, but while we were playing together the energy was the same as playing with people in the states. The key calls were in English, and really that's all that's needed to jam on a song.
Talking with the bar owner afterward I learned there are no violin teachers on Samui! And I've talked with a couple locals with a desire to play violin. I think a trip to a couple music education outfits is in order.