it's kinda the same over here. it has only been recently that our group has been getting recognition from national groups. (did we really have to do really well last semester to do so??? i don't know...) don't fret over it. you joined your local because you wanted to and enjoyed the sisterhood presented at rush. if you worry about what others will think of your group (you=whole house) then morale can drop and then your sisterhood will too. when our group upped our sisterhood and all looked like very happy sisters, people noticed.
kill them with kindness. if the others seem bitter at your presence on campus, just be extra sweet to them. it works somehow...