When you say context, I'm going to assume you mean two separate sites, with their own webroots, application scopes, etc.
I can't help feeling that a more formalized API between the two disparate systems would be more appropriate. You probably could rig something up by sharing scopes, or extending applications, or even via server scope, but it would potentially create more issues than it solves - i.e, if you had to ever cluster to more than one machine, or move siteA -> serverB etc. There's presumably authentication risks and "literal" scope creep (Application A unintentionally affecting Application B) etc too.
I would setup a controller with a bunch of endpoints as an internal use API which require some sort of authentication on your wheels side, and use cfhttp to POST/GET what you need from the other application. The advantage being that your interaction with the Wheels application would then be more considered, more easily documented and restricted in terms of it's operation.