I know that people who bought Bioshock Infinite Ultimate Songbird Edition for the PS3 will get a email on the day the game is released 03-26-2013 with a one-time-use code to claim rewards for the upgrade pack, Industrial Revolution rewards and BestBuy Bird's Eye Sniper Rifle.
Lets say I have to reinstall Bioshock Infinite at some point in the future.
When you buy anything for a game, DLC, etc from the Playstation Network Store you can always download it again if you need to.
Will I be able to go to my download list at the Playstation Network Store and redownload all upgrade packs, Comstock Bird's Eye Sniper Rifle, and Industrial Revolution rewards that I downloaded when I first got my game?
Everything that comes from the PSN store, whether free, paid for or redeemed a code for will always be available on your download list under Account Management/Transaction History on the XMB, even if it later becomes unavailable on the network.
I know this for a fact, because Qbert, Joust and a few other games are still on my Download List, even though they are no longer available on the PSN Store.