Luggage tags can only be ordered by those in GS or above, or Pinnacle Club members regardless of their cabin category. I think agents can order them for anyone but it incurs an extra fee.
Porters have always been able to tag bags. It used to be just regular tags that they'd write your name and cabin number on. However, on our Oasis cruise in June, since we'd been upgraded to a GS the tags I had printed out were no longer any good, so the porter had to give me new ones. They seem to go to a little more trouble now and have blank tags with the ship outline on them so they can highlight which part of the deck your cabin is located. This is due to the luggage loading process used. Those with RCI tags know what I am referring to.
Your luggage should also be expedited and arrive at your GS sooner than normal.