In a pinch? make a quick vinegar solution (1 tsp. vinegar in 1 quart of water) and spray the stain. let it sit for ten minutes, then blot, rinse and wash.
How to Remove Tea Stains From Cups, Surfaces, and Clothes With Bleach
Follow these tea stain removal steps to learn how to use bleach to remove tea stains from clothes, mugs, tea cups, plastic, and other surfaces.