No. Alcohol should not make you pee the bed. Unless of course you were so intoxicated that your central nervous system was so depressed your bladder couldn't wake your brain to give you the sensation you have to go to the bathroom and wake you.... and that would involve a nearly lethal amount of alcohol which it doesnt sound like you guys had. If you drink so much that your body can't wake you to pee, it might not be able to wake you to remember to breathe... scary stuff.
Do either of you have a history of bedwetting? If not, was there anyone else in the house with you that could have played a prank? The hand in the warm water joke, or something like that?
A lot of people get very drunk and pass out and still don't wet the bed, It would be very unusual and the fact that both of you did it.. makes it even more unusual still... that is unless either of you just have a history of it and coincidentally did it on the same night.
If you have a weak bladder, have to urinate frequently , have trouble holding it... alchohol could definitly make that worse. Your body reacts to it like it does poison, it wants to be rid of it asap which is why it will make you have to use the restroom more than other beverages.
I know teenagers like to experiment, and telling you not to is going to fall on deaf ears likely, but you really should not be drinking alcohol at your stage in development. Theres a lot of damage that can be done, not to mention the dangers of drinking more than your body can take.