I don't see why not. Biscuits are used now for alignment by some. The Dominos would just be tighter and more accurate (if done right). Since the alignment will be of just the top surfaces, I would use the widest mortise and make fitting easier laterally. You don't say what the top is made of, so I assuming since you are able to cut holes for the Dogbones, the material can be cut easily with the Domino cutters.