Where's the love interest?

It's totally up to you. With my WIPs, in one story, I have them dating already from before the story even begins and in my other WIP they start dating within the 1st 50 pages and the rest is about their relationship and other stuff. There is no one correct answer.

Seems to me that if she's dreaming about him, that's his introduction.

If he's mentioned in dreams I don't think it's necessary to rush to introduce him.

Actually, I've found it's only when re-reading books I get annoyed if the LI isn't introduced quickly. First time round it never really bothers me when they're introduced because I'm already intrigued by the rest of the book, but I just read this book again where the LI isnt introduced until half way through the book and I was itching for his entry just because I knew it was coming.

In my current MS my MC doesn't ever actually have a present scene with her LI, she just re-tells things that have happened between them in the past.

Dreams seem like a pretty good introduction if you ask me!

It's never too late or too early to introduce the love interest. Some stories don't even have a love interest. Some end with them getting together on the last page. Hell, I'm sure some even end with them meeting for the first time on the last page.

The only question that matters is what makes it the most awesome story.

Dream sequences definitely segue into your love interest...in my opinion!