Indie is about as specific as jazz. You can spot an indie band when you hear it, just like you know what classical or jazz sounds like, but that is where 'indie' stops being descriptive.
By the definition of indie, an indie bassist would be any bassist who plays for a band signed by an independent label. You can't characterize his/her sound by that definition alone.
I disagree to your jazz comparison actually. I would compare the general blanket term of "rock" with jazz.
semantics have no place in rock...hahah