Diver300, I built an RFID radio in 2014 designed to listen to the door reader itself and not the actual tag which was basically a two coil system only the two coils are spread out over some distance. The idea is pretty simple. When you place a RFID tag near a reader, the reader becomes a modulation transmitter. The whole idea was not for nefarious attempts, but to exploit and present a vulnerability at a national security conference held in Las Vegas that year. Initially, myself and a friend of mine that works as a Penetration tester conceived the idea and set out to design a proof of concept. Our goal was to come up with something that would only work about 3 feet, but instead we ended up setting a record for a valid read at 25 feet.
So as far as I know, unless you have an active tag, meaning that it is powered, you won't get the distance. Some of the higher frequency tags (13.5MHz) will go further, but the principle is the same. Unless they are powered, then they are generally limited to a few feet.
EDIT- The "pickup coil" that I used to achieve that distance was only about 3 inches in diameter.