A good bassist should be able to do what the gig requires. For a college audition, you ought to be able to play with solid feel and tempo, conveying some reasonably schooled sense of basic and extended rhythm and harmony. You should also have your reading chops together.
*But* what exactly is non-negotiable and what is unspoken-but-valued will depend on where you're applying. For example, when you are able to select your audition pieces, some programs will want upright chops and will prefer if you lean on orchestral or jazz audition pieces. Some programs will be fine with electric bass and musically literate rock or pop audition selections. (Berklee, for example, advises that you audition on what feel to you like your strengths; so don't try to hit them with a baroque fugue on doghouse if your whole thing is Wooten style slappery.)
If in doubt, ask (not us, but the program to which you're applying).