I don't believe McCain ever attended Hagee's church (except maybe once to give a speech or something).
I believe you are correct (I could check the Internet real quickly - but I'm lazy ... albeit, I'm not paid like Frank Rich to pump out articles - so he has no excuse). I'm pretty sure Mr. Hagee is based in Texas, whereas Mr. McCain obviously splits time between Washington DC and Arizona. There is no way that Mr. McCain is a member of Mr. Hagee's church. Perhaps he has voiced or provided some support, or acknowledgment of Mr. Hagee in the past, but Mr. McCain is not member of Mr. Hagee's church.
Hagee and McCain share a symbiotic relationship that has nothing to do with church membership. Hagee believes he has a Christian Zionist-style ally in McCain, and McCain no doubt gets a large influx of cash when he appears in the San Antonio church.