Is this Water Hammering?

I have a problem with my bathroom tub facet. We renovated it like 4-5 yrs ago. Put in claw foot tube, new fixtures(bought online don't remember where), had some new copper piping done. I think for past yr +/- the pipe vibrates and looses water pressure fast. It only happens to the bathroom tub facet, and only for HOT water supply. I think its the steams(hot, cold), but I cant get new ones anywhere bc everything was specially made. I am totally baffled. It's driving me nuts. Home Depot recommended a WATER HAMMER??? I tried bleeding the air out of it multiple times, still the same. Any ideas???