Well back that bus up-The Twitter rep for delta admitted she was wrong:

Delta Assist ‏@DeltaAssist 53m
@JKF1897 I'm sorry. I've further reviewed the guidelines for the one-day pass and you are able to use the pass in additional lounges... 1/2
Delta Assist ‏@DeltaAssist 54m
@JKF1897 ...on trips with connections. *KM 2/2


I understand buying passes on Ebay might violate the terms-but I'm not concerned about that. It's the same if you buy red sox tickets outside of the park before the game. You take that chance. However the seller risks me posting a negative response saying "pass was invalid/bad etc if thats the case.
If Delta is posting them on ebay they are violating about 10 different Ebay rules nevermind entrapment. Plus they would need to get a life. Fly the planes!