I don't know why you've chosen JSF for web development, but one of the
most issue that JSF persists on, is to simplify the views and to move
the complexity to controllers and models.
I don't believe JSF needs such a iterator you are searching for,
that's why you can't find it.

I do know exactly what are going to do, but i guess you are displaying
a string collection in a column of datatable.

There are three solutions
1. Converts the array to a string in the model
2. Use the following code

<h:dataTable var="b"value="#{PollJSFManagedBean.retrieveCatQues}">

<h:column>
<h:outputText value="#{b.title}" />
<h:dataTable var="cat" value="#{b.tbQuestioncategory}">

<h:column>
<h:outputText value="#{cat}"
</h:column>
</h:dataTable>
</h:column>
</h:dataTable>