A while back, the Citi website erroneously advertised that the Prestige card will earn 3x on gas and some other purchases in the broader Travel category. This offer was a mistake: only  the Premier card has the more extensive Travel category while the Prestige only gets 3x on airlines, hotels, and travel agencies.
Via flavorpuff on Reddit, Citi is now sending out a letter to those who applied under that offer will get the 3x rate honored for one year from signup, then it will revert back to the regular terms.
The broader 3x category is the same as the Premier 3x category: Airlines, hotels, car rentals, travel agencies/travel aggregators/tour operators, gas stations (including gas purchases made at warehouse clubs and convenience stores), commuter transportation, subways, taxis/limousines/car services, ferries, railways, cruise lines, bridge and road tolls, parking lots garages, campgrounds and trailer parks, timeshares, bus lines, motor home/Rv rentals, and boat leases and rentals.
It’s a bit weird because over four months have gone by since that time when people applied for the card under those mistaken terms. Apparently, the legal department finally decided now that they have to honor it.
To reiterate, this only applies to those who signed up for the card during a small window near the end of January 2016. You should get a letter in the mail if you are eligible for the 3x rate on the broader travel category, and the higher rate will be in effect until some time around the end of January 2017.
Received my letter today. Wish they would have informed me sooner. I had assumed it was an error and haven’t been spending on those categories. I will now until end of January 2017.
Depending on which CCs you have, this news is totally useless even if you got it.