Is companion planting just as benefitial in containers as it is in the ground?

It's always a good idea to put like plants together,same sun and water requirement.In a large pot, the center piece is called the thrill.the surrounding flowers or plant is called a fill.The third and final is called a spill.Use colors that compliment each other ie;yellow,purple,red, orange.Annuals bloom all summer,if they get leggy cut them back.Deadhead to keep those blooms coming.Grasses make great container plants.One of my favorites is purple fountain grass.Ivy or sweet potato vine does great too as the spiller ,the one that drapes over the pot. Good luck,