Maybe I am a bit too slow but I can't really see what is significant in this quote by Kripke. Firstly, things are not so exactly perceived by us through our senses, to be given an exact name. For example, a borderline colour between yellow and green might once be called yellow at one occasion and green at some other occasion. Therefore even technical names are not to be taken very seriously in specifying the identity of an object. There is always more than we know to an object, which might eventually cause a differentiation. Secondly, when we call something water, it is equal to saying that 'that thing affects me in a particular way'. It might be any chemical compound but it has nothing to do with what I call it.Therefore "water is H2o" is not inclusive, whereas it is cleverly used to mean that water is only H2O (In this quote). You can conceive of 'water' just as a general term. We use lots of these names throughout our lives. Liquid, for instance, is the term we use to call something by certain properties which are known to us. Thus alcohol is as much liquid as water. Stating that 'what you distinctly perceive as water might in fact be another compound', is wrong. In fact, it is not another compound but just a kind of water (subcategory). You might just as well say "Alcohol is a kind of liquid."
In the case of tea, it is not a referential failure at all. What we call tea, is a mixture of a substance and water, not a substance.