@MattW, 
@Veer
I haven't managed to look into it in great detail, but this is what I did to get it working so far. Add the following to both xengallery_media_view and xengallery_album_view templates (anywhere is fine):
	
	
	
		HTML:
	
	
		<xen:if is="{$xenAddOns.Tinhte_XenTag}">
    <xen:require css="tinhte_xentag.css" />
    <xen:require js="js/Tinhte/XenTag/bb_code_edit.js" />
</xen:if>
	 
 
That will get it working.
@xfrocks is this something you can reproduce on your copy with the more recent XenTag updates? Any idea what changed?
Just for reference, the comments are loaded in via AJAX using the XenForo tabs (like the profile tabs), the template that is returned contains some of my own JS, plus the standard XenForo editor. When XenTag is enabled, the comments tab does not load.