I've downloaded tet1.66-full.exe and tet1.93-update.exe
I ran them in my Windows installation to create the TETurkhan folder and three .bix files. I put these into /Applications/Civ III Complete/Play the World Game Data/Scenarios/
I was then able to launch PTW (note that it's a PtW scenario, not C3C), select one of the .bix files using Load Scenario in PTW, and start a game. The Civilopedia correctly shows the Gaia Generators. I haven't tried playing any of the game, so I din't know if it will fail later, but it seems to start up OK.
PS. Stuffit Expander will expand the downloaded .exe files on a Mac. You then need to merge the patch into the full mod carefully to avoid deleting unpatched files and folders.