Most struts tags are designed to work with a javaBean. A Vector is not a javaBean. Therefore, in order to do what you want using struts tags, you will need to embed the Vector in a javaBean. Usually, in Struts applications, you embed the data you're working with in a bean that is a subclass of ActionForm.
If this doesn't fit your model, then don't use Struts tags. Use jstl, or just plain old scriptlets.
Keeping in mind the above explanation, here is some code that will work: