Maybe it could be. Could you bend the calcium in someone's bones? I mean, you could certainly bury them with ease. And then you could use it to excavate rock and mineral.
With earthbending? Like bending a chunk of earth beneath you to carry you? I guess... But you could use waterbending for that too, unless you mean lifting your skeleton up with earthbending. Ooh, you could rip a person's skeleton from their body this way.
Air, logically it is the most powerful element. Displacement of air would allow you to fly, instantly destroy your opponents, remove the ability to have fire and water available to your opponent and dissipate any earth attack thrown at you.
FIRE
FIREEE
I was thinking more along the lines of flying...