In the situation you mentioned, I think 들어는 봤어요 is a good answer. An alternative could be: "얘기는 들어 봤어요." (I've heard others talking about it.)
In general, 들어는 봤어요 is not exactly the same as "I've heard of it," because -는 here implies that "I've heard of it, but I did not _____."
(And yes, -어는 봤어요 can be used with any other verbs given the right situation.)
For example:
A: 춘향전 이야기 알아요? = Do you know the story of Chunhyang (a famous Korean folktale)?
B: 들어는 봤어요.
A: ???
Here, B's answer implies that he heard about it, but he's not comfortable saying "yes." Maybe he forgot the story; maybe he heard a highly abridged version, so he doesn't think he really knows the story. Or something else.