The Ursack AllWhite withstood an hour long bear onslaught this summer in West Yellowstone. (That was enough for me, so that is what I have now.) It has been approved by IGBC, but last time I checked Yosemite's website was last updated early last year.
On the Whitney trail, you need to protect your food from marmots and mice, and I am sure the new Ursack will handle that. As for official approval, though, I am not sure.
Why don't you call the Wilderness Permit office for Inyo N.F. (760-873-2483) and ask the question. I would sure like to read what you find out.
