At SFO T3 domestic check in, I was instructed to tag my own bags by an agent working the Premier 1K line. After I was done tagging the bags, the Premier 1K counter agent refused to take the bags and told me to go to the general bag drop. He said if I had not tagged my own bags, he would accept the bags and tag those for me, but since I already tagged the bags I had to drag them to the proper bag drop counter. Not a good experience but that's just a short interaction during a long travel day. Oh well.