Just got done failing! :-)
Yes, you must have a basic understanding of EJBs to include security and deployment. You must know the particulars of JAX-RS and JAX-WS as implemented as EJBs.
Not in-depth, but you need to know. Also, see my
thread on why I failed. Don't neglet rote "wikitrivia" memorization on the topics. If it's a webservice topic and is described using a bulleted list (memorize the darn list).