Unfortunately, we have yet to seen any kind of "official" treatment dealing with Alaundo's prophecies. There's likely some fan-based works out in the ether reaches of the web... so you may wish to try a google.
Interestingly, we know one prophecy of Alaundo's has recently come about -- that of the Devil Dragon Nalavara's assault on Cormyr. The novels Beyond the High Road and Death of the Dragon have the details...
Wasn't one of his prophecies in Spellfire? I seem to recall Elminster and Lhaeo discussing it, while Narm and Shandril were staying at Elminster's tower...