Adding milk to hot tea scalds the milk, altering its taste which some people find unpleasant. So milk first for tea.
Adding milk to hot coffee does the same, but the scalded milk taste adds flavour to the coffee - it's how cappuchinos are made after all.
YOU NEVER PUT MILK IN TEA FIRST! I like my cuppa really strong so i put water in so that the tea gets a chance fully infiltrate every particle of water,when you put the milk in first,hardly any tea comes out of the teabag and you end up with basically milk and water! With coffee it does'nt really matter but i always put the coffee in first out of habit!
If the milk goes in first,the tea will end up light and weak! Not the way i like my cuppas at all! Coffee,same as the tea,put the coffee in,sugar,water then milk till you get the right consistancy!