So generally you can refill tea bags with hot water several times before the concentration of the tea bags becomes too low to be worth the trouble of filling it up again. So the question is - what equilibrium process prevents the water from becoming dissolved with more tea? Does the water get "saturated" with the tea powder? (can tea powder really be "dissolved?") And if you add two tea bags into the cup, do you shift the equilibrium direction or not? If water gets saturated by tea powder, then I think it wouldn't. but if it was merely a mass exchange process (similar to diffusion), then I would predict that it would.