I think MLB.tv is available in every country except Japan, if I remember correctly. I've been meaning to test it when I'm traveling, but I've never remembered to do so. I was in the UK last summer, and I think I could have watched the Mets on the phone app, but with the time difference and the busyness of traveling, I never got to try it. Since I live in the Philadelphia market, I can't see Phillies games on the app. I was in Boston two summers ago, and meant to try seeing if I could, while there, watch the Phillies and not the Red Sox, but again, I forgot to give it a try. I expect, though, that that's what would have happened.