I don't know, that seams Lazy.
Like, Hashirama is listed as using Yin Release, but he's listed as using all of the elements and he only has the one confirmed Yin Release technique.
Hashirama is said to have had an unusually potent life force, so if anything his powers are more Yang than Yang rather than "Yin-Yang."
Photosynthesis seems more like plain wood...
Maybe just "both become more versatile and powerful" until we come up with something better?