I'm attempting to show inline comments after each publish on my small category page using comments_template() tag.

However, your comments ought to or comment form aren't turning up for whatever reason. Exactly the same tag works fine around the content-single page.

Incidentally I'm using Wordpress 3.2.1 together with the twentyeleven theme.

comments_template begins using the code:

if ( !(is_single() || is_page() || $withcomments) || empty($post) )
   return;

To ensure that only works best for posts and single pages.

You may either produce a page that lists your groups as well as uses comments_template. Or use get_comments to obtain all comments for any publish after which by hand loop through them and create the output. You may also set the worldwide variable $withcomments, see answer from sbrajesh.

You'll be able to achieve this by forcing the loading of comments. You are able to pressure loading of comment by setting the worldwide variable '$withcomments'

For instance, place the this code inside your functions.php

add_filter('wp_head','sb_force_comment');
function sb_force_comment( ) {
global $withcomments;
    if(is_category())
        $withcomments = true; //force to show the comment on category page
  }

It'll show your comments ought to along with the form too around the category page if you work with comments_template() in your category page.

Just in case you won't want to show the comment form around the category page, it can be done by putting the next code inside your functions.php

add_filter('comments_open','sb_fake_comments_closed_on_category',20,2);

function sb_fake_comments_closed_on_category ($is_open,$post_id){
  if(is_category())
    return false;
  return $is_open;
}

Hope it will help :)