Well, they can see some affiliations at some restaurants. I know an AP icon shows up on the hand held scanners...but not all the time. Even so, the problem is how much programming do they want to do, and is it cost effective for Disney to do so?
For instance, a restaurant tab is already calculated, you've told your server you have DVC or AP or TiW, and the bill is finalized. Since the MB scan is completed AFTER that, and affiliation that would be automatically linked to the MB would have to be recalculated after the payment scan is already done, a new itemized bill generated and so forth. Now, it could be done to do all that, but is the cost to do so really worth it to Disney, especially when you consider DVC, AP and TiW are all different divisions of the company. And now that we can use the phone to show our DVC and or AP card,upgrading the MB affiliations would seem less of a convenience than if we actually had to dig out the physical cards. Virtually everyone has a cell phone or tablet with them these days, anyway.