If I decide to delete TEW from my PS3(getting a bit cluttered) will I be able to revisit the DLC later on or is that content not part of the retained data? I hope I'm explaining this clearly enough. Thanks

As long as you didn't delete your save data, you should be able to return to your game saves. You can learn more about managing game saves for PlayStation 3 at this link:

https://support.us.playstation.com/app/answers/detail/a_id/440/~/manage-game-saves-on-ps3