In that case air is "water-benadable" because it contains water aswell
They could only bend the salt
I think this would be similar to how water benders can get water from the air. The air has water in it, but they can't bent the air, only the water in the air, so earth benders can bend the salt in water, but cannot manipulate the water itself.
Earth benders could.control armies of undead,
No it isn't.
In that case air is "water-benadable" because it contains water aswell
They could only bend the salt
I think this would be similar to how water benders can get water from the air. The air has water in it, but they can't bent the air, only the water in the air, so earth benders can bend the salt in water, but cannot manipulate the water itself.
Earth benders could.control armies of undead,
No it isn't.