Can a wildcard use the original team ability and the ATA that on the original character? Or does the wildcard have to chose one, either the original TA or ATA?

The wildcard can choose one or the other. If the wildcard also has the ATA from its keywords, though, it can copy the printed ability from the other character and use both.

The way you have this phrased makes me suspect that you may still be using the old method for ATAs which replaced existing ATAs. I wanted to mention that this is not the case.