Dorsal and ventral are synonymous with posterior and anterior, respectively.
Furthermore, if you use them interchangeably, you won't ever be wrong, but just be aware that there are times when it is more appropriate to use one over the other.
For example, you would always say the ventral or dorsal mesentry or aspects of the hands or penis, however you would be more inclined to say anterior abdominal wall versus ventral abdominal wall.
In relation to your specific question, Sonic hedgehog gene regulates polarity at the base of the limbs, whereas Wnt-7 produces organization at the distal ends of the developing limbs. Since the latter is distal, it fits better with the ventral-dorsal description normally afforded to the hands/feet, whereas the former is more closely associated with the trunk, and so it receives the trunk-association.
