You want to make sure your surface to-be-tiled is as inert and clean as possible. This means not a lot of flex and clean up the bacon grease. If the existing paneling has a lot of flex, you should think about adding a tile backer board before tiling. Most RV's don't need it.
If using a glass, stone, or vitreous tile, an organic tile mastic is the best. Larger tiles (6" X 6" or bigger) are probably best to set with a cement based thin-set. For anything under 1/4" grout space on walls, an unsanded grout is used. Most of them come premixed with a polymer additive but a liquid latex additive can be used, also.
I've done a bit of tile setting in RV's and it is a good modification for certain areas. My rig has a tile entry and a tile heater surround. I chose to use sheet copper for the stove backsplash because I had some on hand.
Good luck with your project!