I asked a Team USA Minnesota rep the same question about their affiliation. Here's the reply I got...
It's a sponsorship issue with the shoe companies - as part of the contract arrangement with an athlete, the shoe companies stipulate that an athlete cannot list the USATF club where the athlete trains even though the club in many cases provides more funding to an athlete than the shoe company does. This is an issue that USATF has been working on but to date it has not been resolved. Since all of our athletes have shoe contracts (which certainly helps Team USA Minnesota a great deal since many of these contracts take care of travel expenses), you will not see Team USA Minnesota listed next to our athletes' names.