I'll start out by saying that I am an intern for a literary agent and deal with the slush pile every day. I've only been doing this for a few months, but already learned a ton so hopefully can help some.

Nicholas Foster is facing the moment every young person dreads most.

Right off, this line isn't a hook. What is the moment every person dreads most? I want something that catches me from the first sentence. This is too vague.

His dream job creating fantasy artwork is hanging by a thread, his new boss hates him and his girlfriend is openly wondering if it's about time for him to grow up already. Worse, as the stress in his life is creeping towards a fever pitch, he begins to have a series of strange nightmares, in which people and creatures from his artwork appear to recognize and beckon to him. Then, just as his professional crisis forces him to wrestle with whether his dreams can possibly come true, he finds his answer in the most unexpected way when a knock at the door reveals the same old man he'd dreamed the night before, bearing a grave warning and an astonishing tale.

This is coming off as too much of a synopsis. Queries are character driven, not plot driven. This should be centered around Nick and his goal, motivation and conflict.

REVERIE follows Nick as he stumbles into a world that seems to spring from the depths of his most fevered imagination.

Introduce your title as your closing paragraph where you give us the word count and genre.

He will visit incredible worlds, learn what dreams truly are, and discover the long-forgotten true story which forms the basis for our myths and archetypes, until at last he finds himself faced with a terrible choice - to return to the world he's always known, or leave it all behind to fulfill a destiny as old as mankind itself.

Very very vague and cliched. We want details in a query.

As for the bio, don't add one unless you have writing credentials. Your last paragraph should be title, word-count, genre then thank the agent.