Probably one of my favorite episodes of Young Justice is "Drop Zone". It features a mission the young heroes under take in Santa Prisca only to find a power struggle between the forces of Bane's drug cartel and Kobra who's trying to move in on his territory. I'm sure by now you all know how Kobra has been a regular nemesis for both Task Force X and Checkmate. And although Bane has tussled with Checkmate before his history with Task Force X is a bit different. He was "recruited" by Amanda Waller at the end of the 2008 "Raise the Flag" mini-series. But his stint with Task Force X was pretty short lived and apparently his "service" was brought to an abrupt end when Waller banished him along with Deadshot to the prison planet in Operation Salvation Run #2. Which probably explains the how they came to work together as part of The Secret Six I'm guessing. Dan, you wanna weigh in on this?
I highly recommend this episode of Young Justice! You can catch it out on Youtube, here's a link to part 1 of 3: http://www.youtube.com/watch?v=fd1KPcJIUSc