Clementi for college audition?

I would agree that it seems on par with Mozart's sonatas and therefore should be fine. However, you might want to check, if you're applying to more than one school, that all the schools' requirements simply require a "clical sonata" -- sometimes they specifically ask for Mozart, Haydn, or Beethoven (I even saw one school that only wanted Beethoven when I was auditioning). If there are no specifications of composer, then by all means play the Clementi. Good luck!