Both colors are peeling. It looks as though you put the green down first and then overlaid the yellow. It still appears that something is running down and lifting your vinyl. However, how it runs down and only attacks certain areas and not others is rather peculiar. If the vehicle had been contaminated to start with [improper cleaning].... it would've had to contaminate the vinyl before you overlaid it for the second color to peel, also.
Generally, when company's clean these things, it's from top to bottom. They let gravity do most of the work. With this rear picture, I don't know why they'd be cleaning this harder or using more chemicals than on the side.
It doesn't look like the vinyl was installed improperly, but you might have to do this over for nothing. The manufacturer will probably find an excuse, but if they're nice, they'll at least replace your material cost.
I'd place a claim with your distributor and in the meantime, make full sure... your people are cleaning this correctly.
The only thing I would say could be your fault is if someone used the wrong application fluid if you used any at all.