Hi Liz,
When you say 'latest edition base game', do you still mean the base game in the original artwork? If so, then yes, it will work. My collection is made up of expansions from lots of different publishers including Filosofia. Because the game is language-independent (except for the original Wheel of Fortune), you can mix and match expansions from different publishers without any problems. You'll obviously receive the French rules for Inns and Cathedrals, but we have the
Complete Annotated Rules in English available for downloading.
If you mean that you have the new artwork for the base game but the expansion is in the old artwork ... well, then whether or not it 'works' depends on your personal point of view. You can still play them together because the tile backs are the same, but there will be a clash of artwork.