Wii save data on the Wii U
The save files are compatible if you play the original Wii VC game in Wii mode (an option on the Wii U menu for playing Wii games), but not with the upgraded native Wii U VC versions of the games.
The save files are compatible if you play the original Wii VC game in Wii mode (an option on the Wii U menu for playing Wii games), but not with the upgraded native Wii U VC versions of the games.