NO to T&G composite decking, heavy, thick and no it won't keep water off of the foam. IMO, the foam getting wet repeatedly isn't the primary concern w/ using T&G decking, it's the weight and thickness that would concern me more.
If you are referring to space age composite plywood substitutes, or the honeycomb 'aluminum' composite sheets, they aren't T&G. They are lightwieght and not any thicker for a given purpose then typical ply, but they are quite pricey. Since they aren't T&G, I suspect you are referring to the stuff made for decks.
My suggestion is to use the best plywood you can afford, seal it well with the best sealer you can afford, use whatever flooring material you prefer, keep the boat bow high, with the plug out and the boat covered and maintained.
She is throwing a nice wake, must be running good.
