Would a mine launch a small bus into the air?

A Ford E-450 specifically.

It would take an extremely powerful mine. While it will lift the bus a little (MAYBE an inch or two), the wheels probably will not even leave the ground. Most of the force will escape from around the bus.

Hm, I suppose so.

It would be kinda cool.

As long as the bus is empty and there aren't any other people around.

A few years ago I saw an experiment were some scientists tried to launch a bulldozer into the air using ANFO. The bulldozer was torn apart. I don't know if a mine would be as effective as the ANFO they used there but if by "launch into the air" you mean almost LITERALLY launch then it would most probably tear apart a bus.

No. Mines are high explosives and shatter metal. You are thinking of a low order explosion, like a natural gas explosion… That will lift it a bit without tearing it to scrap.

If it was an anti-tank mine, it sure would. An anti-personnel mine would not.