Exams often have silly requirements, and in fact often depend as much on what you don't know as what you do know. So the only real answer to that question is to check and see what the exam itself demands.
In the Real World, some people like JSF and some do not. Some of our most venerable Ranchers are very much in the servlet-and-jsp camp. On the other hand, I find it very useful. So much that I've hosted the JSF forum here on the Ranch for quite a long time now.
I'm sure at least one/some of the exams will specifically
test you on JSF, simply because JSF is part of the JEE standard. But so are JSPs and
servlets. So ultimately you need to be comfortable with both paradigms.