The pattern you linked to cannot be accurate. I have my Wii going through a DVDO Edge video processor and I check my Wii's black start-up warning screen against the pure black sidebars that the processor produces when in 3:4 mode. I tried making your pattern "correct" and it goes WAY below the black of the processor. Also, the setting of my Wii is matched pretty much exactly with the brightness setting on my other inputs.
As for the in-game patterns, they are useless for any accurate calibration. The developers only include them to make sure that your display is not so dark that you just get a black screen when you're supposed to be seeing a darkened corridor, for instance.