Whenever (*) you use a heading (h1-h6), you may also use section (**) to wrap this heading and its content. You can read more about this in my answer to a smiliar question.
May, not must.
The HTML5 (CR) spec says:
Authors are also encouraged to explicitly wrap sections in elements of sectioning content, instead of relying on the implicit sections generated by having multiple headings in one element of sectioning content.
So it’s encouraged, which is a yes to your question.
(* Except for the site heading, i.e., the heading which is a child of body and of no other sectioning content element.)
(** Unless the content is appropriate for article, aside or nav.)
I read that any related content should be wrapped in
This is not true. "Related" can mean many things. Follow the definition in the spec. Be aware that section (and the other sectioning elements article, aside and nav) play a role in generating the document outline.
