I've always been a MAC/Reunion guy, and have found no direct way to transfer PC data to MACs or vice-versa via GEDCOMs although I guess in theory this is supposed to be possible.However, since HTML seems to be a "universal" language; i.e., my MAC word processor can read PC word processor posts and vice versa (with a few weird characters showing up now and then; it just can't read attachments generated on PC's unless I buy a "converter"), it may be possible that going through the web might work.Specifically, you might try this:
1.Create a FTM GEDCOM using the PC and post it to Rootsweb World Connect and give it a DB name you can remember.It would probably be best to just create a subset GEDCOM rather than the entire 6 years of research to see if this process works.When you set it up, allow for downloading of the GEDCOM from World Connect.
2.If you have anything files already created using Reunion on the MAC, make a back-up copy of them along with a back-up of the basic Reunion software in case the following screws up the program:
3.Using the MAC with Reunion open, go to World Connect, and try to Import your DB from it. See how well the fields show up where they're supposed to using Reunion.
NOTE:Since none of my gen data is in FTM, I have not done this so am not sure what happens when you do.Just think that since I can upload my Reunion generated GEDCOM to World Connect and someone with FTM can download it, the process should work.
Good luck (and if you do try it, let us know if it works).