Well is it not known that NVIDIA cards are usually paired with Intel CPUs?
http://www.scan.co.uk/MindMap/AMD
http://www.overclockers.co.uk/mfrList.php?mfrid=156
OK, from the first link I can see where you're coming from with AMD CPU/chipset/GPU combinations. However that's just a platform, they don't perform any better with a certain brand of CPU, obviously if you discount that some processors are faster ... if anything AMD/ATI GPUs are better with Intel chips as Intel have the current best performing processors.
There's no reason that Intel CPUs should be paired with Nvidia rather than AMD/ATI cards.
Part of the reason AMD/Nvidia combinations aren't as common would be the lack of Nvidia AMD chipsets, and therefore SLI support and marketing for the platform.
But in my opinion, to say that "ATI cards are known to work better with AMD CPUs over NVIDIA cards." is just wrong.