When you buy an additional drink such as tea do you get to 1 give one free as well as the coffee?

You always get one drink free to give every 23 hours. Once you buy the tea option, you'll be able to choose whether you want to give a free tea or a free coffee. Second drink will cost 10 diamonds, 3rd costs 20, etc. It will give the same energy as your coffee does. There is no game advantage to buying tea. It is only a cosmetic change. If you want to help your team, best is to save your tips to upgrade the energy of your drink.