LOL, sibling comment voted to death, because I guess HNers know better than 2 native speakers (I am also one).

If you're talking about Indonesians refererring to Indonesian in an English language context, yeah some of them do this too (like the original commenter I replied to above), I can't imagine a context where an Indonesian would ask someone else in Indonesian if they understood "bahasa", because the Indonesian being asked would wonder "Which language do you mean?".

It would be like a Brit asking someone in London, "Do you speak language?".

But just like there's Singlish in Singapore, there's probably Indonesian English. Another pet peeve of mine is Indonesians using "married" as a verb (in an Indonesian sentence) instead of an adjective.