Do not fear Pet Promise food in fact it was one of the two food I know of that were still safe during the Menu foods debacle.
Taurine is beneficial to cats. The Corn Glutin Meal  is not what I like to see due to recent events but the source of this substance must be evaluated. This stuff does NOT come from China and that should take care of it.
Like most things from China, they produce substandard products- tires, foods, toys and this will continue to happen as long as people support this type of manufacturing. They probably could get better results from Chimps or Orangutans.

Through Google, I did find 1 page on their site where Purina is mentioned:
http://www.petpromiseinc.com/news_page/new2.htm

"Nestlé Purina PetCare will provide the necessary production resources and manufacturing needed to maintain the Pet Promise purity guarantees. Additionally, New Chapter Inc., a leading vitamin and supplement manufacturer in the natural channel, has developed probiotic supplements that will be part of the Pet Promise product line."

Not sure if this means they're owned by Purina, or use them like others use Diamond/Menu etc.

If you read the text carefully, the text says that the manufacturing facilities are used but it does not imply that the Purina contents are used. They JUST have them canning the Pet Promise product. I have been using it for over a year and it is a very good food and I have 11 cats.