Bear canisters are not required but you will want some sort of food protection.
Last report I saw on Limber Pine was on the San Gorgonio facebook page for May 6th. It said the trail was basically clear with only patches of snow until a mile or so before limber pine. Then it was completely covered and you’ll be post-holing the rest of the way.
I’d imagine Limber Pine still having snow, then and SB Peak being completely snow covered. You’d probably need crampons, ice axe and possibly snowshoes.