Not Updated For Current Season
The masteries shown here are not yet updated for the current season, the guide author needs to set up the new masteries. As such, they will be different than the masteries you see in-game.
Ok I just wanted to post this really quick, but basically its a combo of pulls, knock ups and ownage. Basically you want blitz to grab the target and knock them up with power fist. Then Alistar should knock up the target. With cooldown reduction blitz and alistar can pretty much keep the target knocked up indefinitely and pull him again if he gets away. Blitz can do his 1-2-3 combo as an initiator (grab-knock up-ult) and use his ult as an aoe silence/dmg (it has about an 18 second cooldown endgame). Alistar should mainly save his ult for tanking/escaping or in rare cases for that slight dps boost (almost never). Alistar should also spam his heal during the fight (or as necessary). This combo almost always grants my partner and I first blood and an early turret kill. Good luck and I hope this works for you. For the build, tactics, and tips for blitz follow this guide http://www.mobafire.com/league-of-legends/build/blitzcrank-cd-reduction-hardkiller-33613. Alistar should be pretty self-explanatory-just knock up, heal, use ur headbutt to knock people back towards your team/turret (move behind them and bump them while their knocked up), and use your ult for its damage reduction. This team is further multiplyed by other "knocker-upers," such as chogath or xin, or stunners like sion, taric, or panth. If this gets good votes/comments I can always make a more elaborate guide. Feel free to add me ingame ign: Orrakddon (I play Alistar), and my friend rroldgeeser (he plays blitz). Please leave a comment if you vote on how it worked for you or suggested improvements (I'm sure it could still use some work + it needs a guide to go along with it).