Just to clarify, EA is not a part of VW, it is an entirely separate company. They get 10 years of funding from VW, but VW has no say in their operations. So far Porsche and Ford are supporting plug and charge, albeit not very well. The EA App works very well in my experience and provides the choice of a discount if you pay a monthly fee ($4/month). I do not pay that fee since I have not been using DFDC that much, as of now. $0.43/KWH without fee, $0.31/KWH with fee.
Since I just ordered a Mach E, I have been checking out the forums regarding plug and charge, and have also watched some on-line videos. It is really unreliable and many have just shut it off, and use the EA App instead. Mach E customers get 250KWH of free charging on that network, paid for by Ford. Also with the plug and charge, if you have the monthly fee discount on KWH, that discount does not apply when using plug and charge with the Ford Pass. That is another reason some people are not using plug and charge, especially after running out the free 250KWH. Many other car makers have offered some free charging initially with new cars as well.
My point about plug and charge is that it is a very nice feature, but both Porsche and Ford have had many issues with reliability, because it is not mature technology at this point. I do believe it will improve in the future.
Eventually, I think all car makers and all charging networks will get on board with plug and charge. The car and the charger have to implement ISO5118 Standard. Apparently Greenlots has it with Ford also, but I have no idea where they have stations, certainly not in Arizona. As far as partnership, it is mainly a matter of getting a billing system setup between the companies, not anything technical.
At any rate, I have zero concerns about being able to charge my Bolt, Mach E or Hummer on the EA network.