If you are referring to something akin to BKK Premium Flight Services, I don't think such a thing exists, not at YVR anyway. It would be very un-Canadian to have such a service
If the airline you are flying with deems you to be a VIP, then they will arrange for an escort through INS, Customs, security etc.
Speaking from YVR experience only, the wait times for INS have never been more than 10 to 15 minutes. As GGlave pointed out, the priority line for security is laden with people who slow the system down. The only thing I can imagine an escorted trip through all this would do, is take you through INS a little faster and maybe push you ahead of the wheelchairs and strollers at security.
You may save 10 minutes overall.
YVR transborder is usually very effecient, at least has been for me on all the times I have been through there.