It took me 1.5 month to pass scbcd 5 (
EJB 3 by Burke/Haefel). It took me 6 months to pass SCDJWS (lots of materials, approximately 10 books, so the scope is like 10 times of scbcd 5).
Some companies are slow in picking up ejb 3 because their infrastracture has already taken other alternatives to ejb 2, like spring/hibernate. New development are most likely going to use ejb 3.
It depends on what kind of applications your company will be doing. For sure, they will have a business and entity layer (ejb, etc.). Web services (scdjws) is used by companies only when it needs to do internal or external decoupling or interfacing, especially with other kinds of platforms like dot net.
XML is well involved in web services. Therefore, if you do scdjws, you get to learn this popular technology (found everywhere, from ajax, to web services, to cellphone data protocols).