The best tea I've tried when I'm short of breath is the Breathe Deep, "Yogi Tea" which is an organic tea with the following ingredients:
licorice root, eucalyptus leaf, basil leaf, ginger root, cinnamon bark, thyme leaf, peppermint leaf , natural licorice flavor, mullein leaf, cardamom seed. You can get it at any local health food stores. It's so good and it's caffeine free. Just in case anyone is interested.