Correcto uso de Assetic en Symfony

config.yml

assetic:
    filters:
        cssrewrite:
            apply_to: "\.css$"
        less:
            node: %node%
            node_paths: %node_paths%

layout.html.twig

{% stylesheets output="assetic/css/test.css"
'bundles/paladinipage/css/test.less'
%}
<link href="{{ asset_url }}" type="text/css" rel="stylesheet" media="screen" />
{% endstylesheets %}

test.less

@font-face {
  font-family: 'Open Sans22';
  font-style: normal;
  font-weight: 400;
  src: local('Open Sans22'), local('OpenSans22'), url('../fonts/glyphicons-regular-faik.eot') format('woff2');
  unicode-range: U+0460-052F, U+20B4, U+2DE0-2DFF, U+A640-A69F;
}
 
body {
    background: url('img/subimg.png');
    p {
      background: url('../img/img.png');
      font-family: "Open Sans22", sans-serif;
    }
}