You have something wrong in your post_count_js macro. I think this code do what you want:
<override_macro name="post_count_js">
<n.param_loop. param="postCount">
<n.if.not.page_user.is_deactivated>
<then>
$('div.post-count<n.page_user.user_tag_id/>')
.html('<n.one_or_many n="[n.page_user.post_count_value/]" one_text="[t]post[/t]" many_text="[t]posts[/t]"/>');
var div = $('div.post-count<n.page_user.user_tag_id/>');
div.append("<br/>");
var postCount = <n.page_user.post_count_value/>;
if (postCount > 20)
div.append("Member");
</then>
</n.if.not.page_user.is_deactivated>
</n.param_loop.>
</override_macro>
Replace it in your marco if you want.