You can probably use the search feature to find this...

but *technically* 1P and above get those, although as a 2P checking into the premier line, I sometimes get the tags. Not sure waht the gold cover is supposed to be for (fun?), but the priority tag means that your luggage is "supposed" to be off-loaded first when you get to your destination.

Your mileage may vary on that. LHR is particulaly good at getting priority luggage off first -- I've never beaten my luggage to the carousel! Note -- I *have* waited for my luggage to arrive on the carousel, until I realized the pile of luggage off to the side had green priority tags on them. =)