Bunnelby's pokedex entry is: "It creates its den by digging in the ground with its large, shovel-shaped ears. These powerful ears are strong enough to chop right through thick tree roots, making them a force to be reckoned with in battle". So it's definitely Ground. Not sure about the secondary typing though.
I am the milkman. My milk is delicious. It's fortified with what the world wants, what the world deserves.