Can I tile up to but not under the sink vanity in my bathroom if it has a layer of plywood underneath it?

My bathroom floor is concrete. I bought some interlocking stone tiles (www.stratastone.com). My dad and I installed a cabinet type sink vanity from Lowes, but put a layer of plywood underneath it first, before I had a floor to put down. We painted the exposed edges of the plywood. Should I remove the plywood and tile underneath the vanity, or can I tile up to the vanity so the tiles will directly touch the plywood base underneath it? My concern is that if water gets on the floor (for instance when my son goes crazy in the tub, or if I ever have a water leak, etc.) would that water seep between the tiles and the plywood and cause irreparable damage? Or would a line of caulk prevent that?