well, you can ignore my last question, however, I have the answer that I think you were all looking for. This works a lot better than locking keyboards to devices, and I think it is what the guy talking about Bus's was eluding to, just didn't mention the last step. So, once you have each keyboard added to your list of control surfaces, assign each one to a separate bus, (A, B, C or D, max of 4 controllers I guess). THEN, go to your rack window, expand the top rack that shows your Hardware Devices, click on Advanced Midi Device. Now it should be fairly obvious. Choose which Bus you want to change settings for, and you now have access not only to which device per controller, but also you can set different channels to different devices from within the same controller. I feel like maybe most people already know this, but for those who didn't, like myself, this should be a big help.

Fantastic answer, sittinghalflotus. It's exactly what I was looking for after being thrown by the "lock to this device" option (which apparently doesn't allow any note data, only controls).

Ah yes, thank you very much.
Process seems a little cumbersome to switch between devices, though i guess the actual process to get it to work made sense.
ta again.

I still can't get mine to work. Im following all the steps.
1. put controllers in buses
2. hardware interface-bus A:device A...etc

When I play, controller A will play device A and B....controller B will only play device B. I want controller A to play JUST device A and controller B to play JUST device B. I'm halfway there...any help?

actually i figured it out.
if it needs to be even more clear
when you select which device you want in Bus A...use channel 1
When you select which device you want in Bus B...ALSO use channel 1

Thank youuuuu!!!!

go to preferences... general or audio tab, make sure the 2 midis are separate, i.e. second option at the bottom (in reason 4). There should be some sort of interface in your rack that comes when you open a new reason project... as a presetting, then make sure you create a mixer, and then create two synthesizers into your rack. Going back to the original interface device, select the advanced audio properties/settings button to view each channel and change the route, midi keyboard 1 to Bus A and select this on a particular channel. Then select Bus B and make this your midi keyboard 2 and also set this keyboard in a different channel. Finally, go back to each synthesizer on your rack, highlight one and right click, and "lock" which keyboard you want to that synthesizer. Then repeat by highlighting the other synthesizer in the rack, right click and select to "lock" the other keyboard to this synthesizer.