Both do the same thing.
The way how water gets oxygenated is by movement of the surface of water. A wave maker and an air pump does the same thing, the bubbles that you see are not oxygenating the water. When the bubbles reach the surface and escape, thats when the surface of water gets disturbed and oxygenation take place.
However, the more you are able to disturb, the more the water will be oxygenated.