No. As long as you pass OCJP of any version, you can take web service certification exam.
I don't have EJB or web component certification and I just started studying for this exam.
Read Java Web Service Up and Running, MZ and Ivan's notes and RMH's J2EE book will help.
Sandra Williams wrote:Do I need to learn EJB first to prepare Web Services Certification? Or should I prepare the business component certification first? Thank you.
You no need to study business component certification objectives to attend Web Services Certification. The certification will not test EJB technology in depth instead it asks questions about how EJB can act as JAX-WS endpoint or JAX-RS resource classes. If you are appearing OCE Web Services exam you also need to understand Singleton session bean type introduced in Java EE 6. You need to concentrate more on security stuffs (role based security on EJB tier) by annotations or by XML files.