Bioshock 2 DLC for Xbox 360 Help?

Yes , as long as you dont remove the Gamertag that actually downloaded the DLC from your Xbox , then all other Gamertags on your 360 will also have access to it. The cool thing about that though is say you go to a buddies house for a week , you can import your gamertag to his 360 and anything that you downloaded on your Gamertag will now be available on his Xbox. Once you go home though you will need to import your gamertag back to your 360 and once you do that your buddy wont be able to use your DLC anymore.