I had a couple of oddities. I called Worldperks and everything seems to have worked out now, but based on what CSR told me, I'd definitely call or your % may get messed up.

Problem 1. My second Turbo trip (DTW-XNA), I finished up my meeting early and switched my return to a day earlier than planned, paying the $100 change fee. The return from XNA didn't post. Meanwhile, I took turbo trip #3, a DTW-CVG full-fare. Outbound to CVG posted as 100% bonus instead of 200% bonus, since Worldperks had no record of my completing the second round-trip(XNA-DTW). I called up WorldPerks, and they posted my return that hadn't posted. She also said she had to delete the oubtound DTW-CVG that had already posted and re-post it, so that it would get the 200% bonus instead of 100%. That posting then went into pending, which led to potential issue #2. My return from CVG posted as 200% but outbound had still not posted and was in pending when I made my second journey of the week to CVG. That outbound posted as 200%. Return on that trip and my original pending outbound both posted with the 300% bonus. I didn't care because it was the same total mileage as I expected since it was the same route, but my inference from the way my miles posted and the comment of the CSR is that the order in which miles post has an influence on the way percentages get applied and could mess you up.