Add bbox from bing to result location. This can be then used in a geosearch_showlocation call fitbounds with (after some conversion):

    var _setBoundsFromGeoLocationResult = function(locationResult){
            var location = locationResult.Location;
            var bbox = location && location.bbox;
            if (bbox) {
                var southWest = new L.LatLng(bbox[0], bbox[1]);
                var northEast = new L.LatLng(bbox[2], bbox[3]);
                var bounds = new L.LatLngBounds(southWest, northEast);
                map.fitBounds(bounds);
            }
        }