I planned to have non-glowing vines and tangles of vines from the start, but there isn't a lot of room left in these tilesets. Between the 2 sets I have 34 ground tile in each color, 28 invisible ground tiles, 65 shadow tiles, 34 glow tiles, 15 background tiles in each color, 8 rocks, 8 vines, and 2 solid black tiles. That leaves me with 7 and 10 tiles for everything else. I'm not sure it's enough.
I was very unhappy with the original vines, and wasn't going to put anymore effort in to them until I consulted the forum. I'm not completely happy with the new vines but I'm satisfied with the direction they're taking me. I would love the glowing vines to be part of a tangled mass of vines as you suggest. I want the cavern to be full of life: worms, grubs, roots, vines, mushrooms, rabbits, etc. I'm sure it will get there. It just takes time.