I just returned from the Vogelsang loop (starting at Lyell Canyon -- the John Muir Trail south of hwy 120 in Yosemite). The woman at the wilderness permit station, where I got both the permit and a bear canister, told me that if I could make it to Vogelsang and use the bear boxes at the high Sierra camp, I wouldn't need to bring the bear canister. I would imagine this applies to any camp site with established bear boxes. Best to call the ranger station to be sure, though.
btw - excellent conditions up there right now. Grass is green, wildflowers are abundant, mosquitos are beginning to thin, passes are free of snow, 40 deg nights, upper 70 deg days. Avoid the low valley, which gets to 90 deg.