In DS9 someone (Sisko?) talks about transporter credits when it came to moving all their stuff to a new house.
Actually, in "Explorers", Sisko speaks of using his personal transporter credits for beaming home from Starfleet Academy every night for dinner. This sort of suggests that the transporter credit is a unit in use in the Academy, but not necessarily anywhere else; Starfleet would have an interest in limiting the movements of its cadets, in essence creating "poverty" and "hardship" for the spoiled brats, but it's difficult to see any other organization deliberately obstructing the use of transporters.
No other mention of transporter credit has been aired in any of the shows.