I wouldn't take a hammock to Point Reyes. A couple camps are in brushy areas, one is on a treeless bluff. The area has some groves of trees, but no guarantees.
Google Point Reyes campsites and click on images - see what I mean. You'll see trees in the background in pics of Glen Camp, but you probably would get a fine for being outside designated campsites. National Park system is not forgiving of being out of bounds of designated camping spots, as I found out in Sequoia when I parked my hammock over a granite slab and let my buddy have the tent area. Backpacking I have no issues whatsoever in California except when there's a designated campground.