Never thought someone else would actually want to know this information let alone ask it on these boards.
I spent most of 2007 in Jakarta Indonesia and I can tell you from first hand experience, XBL sucks in Indonesia. The biggest problem is Indonesia's connection to the rest of the world. It is super small and heavily trafficked. If you can get a connection to XBL you'll be lucky if you can actually get into an online game. Bali would probably have a worse connection than Jakarta since Bali is more of a vacation spot and not a bristling technology hub. Bali is also further away from the international cables that come into the country.
I would recommend leaving your 360 at home. Bali is an amazing place and really needs to be appreciated without any technological distractions. I doubt you will be flying to Bali often enough to make it a trivial experience.
