I have tried to buff out pepper mills that have been finished in wipe on poly... I didn't like the results... I used different methods, the red buffing compound (I've lost the name of it in my head... it's so hollow up there may never find it again), followed by the white tripoli, then carnuba wax,
just using the tripoli then carnuba and just using carnuba alone.... none of them gave me any particular improvement in the shine and I actually think it took some of the shine away.... one thing you might try would be a super fine abrasive paste like Yorkshire grit super fine over the finish... have not tried that yet... I make my own version of the abrasive paste that I used over and/or under the sanding sealer... haven't tried it over the wipe on yet.
I've had success in buffing solvent-based WOP finishes, both with the traditional three-step (tripoli, white diamond, and carnauba wax) process, and with a polishing paste (I used Dr. Kirk's). But the key is to allow the finish to cure thoroughly before buffing.
Solvent-based WOP dries to the touch in about 12 hours, but it takes several additional days for it to completely cure. If you try to buff before it has cured, the results won't be as good.
I've also been successful in buffing water-based poly finishes, but again, the key is to allow it to cure completely - and that means waiting several days. With water-based poly, if you buff before it has complete cured, the finish will actually peel off the surface and look terrible.