It depends on what kind of tea and what kind of future we are talking about. Green tea is reliable as long as the cup is not too inclined when drinking it. On the other hand, I strongly advise against red tea, since its predictions are always disastrous and involve bloodshed. As for the future, if we talk about the immediate future (no more than two minutes) tea-leaf reading is reliable. Even so, the best tea-leaf readers can make mistakes.