Yes, but....

1) no mention of the alliance in the treaty box (and no expiration of 99 years as stated in the game)

2) allies don't ask for help when attacked as stated in the game

3) why would expire in one turn? Doesn't seem WAI.

If the intent of alliances is to permanently lock a faction to peace for the rest of the game with no other features, then I suppose the in-game descriptions are completely wrong.

I reported some alliance weirdness a while back. I have won the game using an alliance victory, sometimes it seems to work properly. However I have seen the problem you described, where the alliance seems to get cancelled after one turn.