Applied for the Amazon Prime store card last year, and my scores were lower at the time so I was approved with a $1k SL. Since then I've used the card pretty frequently for recurring purchases, as well as for a handful of larger orders. I've got some Prime Day shopping to do and went for the CLI--I was instantly approved for a $2.5k increase, bringing my total limit on the card to $3.5k. Not the highest limit in the world, but any win is a good win.
Very nice bump! Congrats.