FWIW, the opf is a bit more complicated than the examples you posted.
Code:
<dc:creator id="cont1">Adrian Nathan West</dc:creator>
<dc:creator id="id-1">Benjamin Labatut</dc:creator>
then farther down:
Code:
<meta refines="#id-1" property="role" scheme="marc:relators">aut</meta>
<meta refines="#id-1" property="file-as">Labatut, Benjamin</meta>