I have tags from a few airlines that I've put on my bags over the last 20-25 years. I wonder if this really does make a difference anymore and if airline staff identify you and treat you different. My conclusion based on my own experience is that these days staff just don't have the time to care and go out of the way to give recognition just by sight of your tag. Nor does my luggage get any extra attention.
25 years ago, in the days when Pan Am had the Clipper Club, you received 2 luggage tags which were made of relatively thick plastic and same size as a credit card. I found that this did work, on sight of it staff would direct you to the lounge when you checked in without asking them. That was a nice touch, but that was it. In those days having a name tag with your details on your bag was quite important as lost luggage was far more frequent than today and luggage tags were secured to bags with elastic or string and therefore prone to being ripped-off. If that happened, and there was no other way to identify your bag, you were SOL. This is less so now given the baggage tags which is actually quite securely attached to the bag.