The Inquirer asked ATI some clarification regarding this page at PCI-SIG. They haven't received any response yet.
The site clearly states that: "Another valuable benefit of the Compliance Program is inclusion on the PCI Special Interest Group (PCI-SIG) Integrators List. This list includes all products that have successfully completed the rigorous testing procedures of the Compliance Workshop".
For ATI cards, you can only see that some old Mach 64 cards have passed these test and that many Nvidia cards including bridged PCX 5300, PCX 5750, PCX 5900, Quadro FX 1300 non-announced NV41, NV43, NV43M, NV43U and announced but unavailable NV45 passed the test.