Welcome to the Forum Kitty;
I would not lay ceramic tile over vinyl for several reasons;
1. it won't stick and your tile will be comming up in several places
2. the vinyl is ever-so-lightly spongy which will break the grout lines
3. we don't know what the former owner covered up with the vinyl
4. stripping to the subfloor and starting back with cementious board will give
a lasting, proven backing for the tile.
5. If you do the whole thing by the numbers you will have a job you can be
I'm sure I will think of some other reasons by tomorrow but, for now, you have enough bad news to deal with. Let us know how it turns out and post some picutres if possible.