https://www.ilibrarian.net/flagmaps/southeast_asia.jpg
Based on that map, I'd say yes that Bali, Indonesia is part of Asia as it is located on the continental crust that makes up Asia, with the Java Trench running just south of the islands which separates it form the open ocean and other trenches separating the Asian continental crust from the Australian continental crust.
Bali just makes it, but it's part of the Asian continental crust as opposed to an island (like Timor-Leste) that's on the open sea between two continental crusts.