I tested it by playing a few different chords and it read some of the notes correctly but not all.
Melodyne does a pretty good job at analysing your audio, but it's not always infallible. In these cases you need to help Melodyne get the detection right. That's what Note Assignment mode is for. See your manual or this video
Also I'm not sure what's the point of using Rewire with Melodyne studio and Reason when Melodyne will pick it up in it's mixer but won't record it. Seems like a cruel joke to me when I still have to bounce the track from Reason to Melodyne.
Correct me if I'm wrong, but isn't it impossible in Reason to integrate third-party plug-ins? That's why the MelodyneBridge or the plug-in variants of Melodyne won't work in Reason. With ReWire you can still establish a connection between Melodyne studio and Reason and always have them play in sync. For the audio routing see our FAQ
> ReWire and MelodyneBridge > How do I establish a ReWire connection from Melodyne studio?