See, you brushed it off just like the film does...but how does he dream her before he meets her? The options he's given at Rekall are nowhere near specific enough to design her so perfectly.
Have you never dreamed about a person that doesn't exist? Even multiple dreams scattered over weeks. Your brain combines features of different faces, or it's a face you happened to see sometimes.
The more important about this dream vs. reality thing is, in the original film: if it is a dream implanted in Quaid's brain, why do we see scenes without Quaid? He wouldn't know about them, and if it's supposed to be a "realistic" vacation experience, he wouldn't dream those moments because he would not be there.