As long as there isn't a big difference in size then absolutly yes. If one was bigger than the outher then the bigger one would swallow the smaller one.
well that also depends on the size of the tank and the current size of the fish. these are both big fish especially the grouper and will grow quickly if well fed.
Maybe you should go with the miniatus grouper since they only require a 120 gallon tank and in my opinion are much more pretty when they mature to adult colors.