You can grow a lot of different vegetables as you can see in the pictures. With hydroponics you don't need as much root space as you do with dirt because you feed the roots with
nutrient solution every 30 minutes or so.
What is more important is the distance between the bottle themselves. The 11 plant is so compact that it is not practical for large plants. 12 inches apart is better and will give each plant 1 sq. ft. of growing space.