I had a Tinker's in my SPS holding tank for about 5 months - all was good. The fish did not nip at any of the SPS I had in there. He went into a fish only after that.
That said, I have been told to be wary of this fish with LPS. The LPS, particularly open brain and other similarly fleshy specimens, are just too tempting to take a bite of and you may see that happen.
HTH