I don't know a whole lot about the GH Waterfarm. It looks very similar to the C.A.P ebb and flow
product which I've heard really good things about. Depending on the variety of tomato, I understand that some can get quite large. The individual buckets should easily allow for ample spacing between sites and assuming the buckets aren't too small, I don't see why you couldn't have a good grow in a system like that.