Need lighting distance advice

I'm growing 4 plants in solo cups in a medium sized closet. they just sprouted 36 hours ago and are about 2.5 inches tall already. I have them under plastic bottles as humidity domes so the light (20w cfl to start with) is about 7 inches away so it doesn't burn the plastic. What is more important; the humidity domes or moving the light closer? I want the plants to be short and bushy. I am getting 65w cfls tomorrow so I don't need to worry about that.