I just tried TVC and airports within 100 miles and Tpa and airports within 100 miles and came up with availability in March for 25000 miles from either Pellston or TVC to SRQ. Use the "more search options" and the "search for "standard award availabiltiy only" feature and if you can the "airports within" feature 100 mile distance.

It also sometimes helps to look by segment ie TVC to DTW and then DTW to TPA and then call them with the flights you've found. I had to do that last night to get to Medford Oregon and Las Vegas using partner airlines. Good Luck and Go Titans