Nothing to confirm except old memories, but Yosemite is full of pines. Unless it is a heavy and wet snow, pines are pretty good about shedding snow bombs before they go atomic; more like snow grenades. A steep pitched tarp will sluff them off without problems. This is a common issue here in Colorado, but it has never caused me any real problems.
Also, consider when you'll be in your hammock; at night. Night is when the temps fall and any snow stuck to the trees generally freezes to the tree until the morning thaw. The mornings are when I start to hear the thudding of snow grenades.
Look up (as always) and you'll be able to spot the trees with snow problems. Look for trees shorter than the others in the canopy and they'll have less snow accumulated on them due to them being sheltered by the other taller trees. Those are the ones you want. Also, prevailing wind in Yosemite is from the west, so camping on the east side of ridges will not only give you some snow shelter, but it will be warm(er) when you are moving around in the morning. Always a nice thing.