I agree with IK's definitions. I definitely have taste, and I am well aware when I like something that is tacky. I consider myself quite good at choosing tasteful items, though I've always had a soft spot for tacky shoes and bright patterns and colours. I wear very few bright colours, despite how much I like them, because they are harder for me to incorporate in a tasteful way. But when my DD was little, I dressed her in stripes and dots and a riot of colour, and she looked fantastic! It is amazing what you can pull off when you are 4!
Style, on the other hand, I admit I am still working on. Style is also more important, IMO. You can have all the taste in the world, and that still doesn't mean that all tasteful pieces go together well. I've even seen people seamlessly incorporate an item that, by itself, I would consider tacky or tasteless yet have it look fantastic (and NOT tacky or tasteless in the context of the outfit they have paired it with).
So I still have a long way to go. I am starting to think that I need to do what some other people do and "pin" more looks and then try to copy them. For some reason, I have a much better feel for decorating a space; I can immediately see in my head what I want to create, and I can look at things and immediately discern whether they would blend in with the intended look. I cannot do the same with looks; I have a hard time immediately seeing why some looks go together and others don't.