The Ultrapod II is designed to handle a load of about 4 pounds (~1.8kg). I think the EOS 30 + 28-135 IS will weigh slightly over 1 kg, right? So it sounds like it should be fine, at least as far as the manufacturer's operating specifications are concerned. You should definitely try it out first, though, because there are other factors to consider in addition to weight, such as whether the whole setup can balance properly.