jena and pellet reasoner not working on symmetric property

I'm using this ontology, generated on Protege. Below is the code.

location = new Location (database);
schema = FileManager.get().loadModel(ontology);
reasoner = PelletReasonerFactory.theInstance().create();
Dataset data = getNewDataset();
data.begin(ReadWrite.READ);
InfModel model = ModelFactory.createInfModel(reasoner, schema, data.getDefaultModel());
String queryString =
        " PREFIX ns:  <http://www.semanticweb.org/ontologies/2012/10/music.owl#> " +
        " PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> " +
        " SELECT ?a ?b " +
        " WHERE {" +
        " ?a rdf:type ns:Artist . " +
        " ?a ns:isSimilarTo ?b . " +
        " }";

Query query = QueryFactory.create(queryString);
QueryExecution exec = QueryExecutionFactory.create(query, model);
ResultSet results = exec.execSelect();
ResultSetFormatter.out(results);
exec.close();

Triple store entry example below.

| http://www.semanticweb.org/ontologies/2012/10/music.owl#Bill Laswell (MN0000075979) | http://www.semanticweb.org/ontologies/2012/10/music.owl#isSimilarTo | http://www.semanticweb.org/ontologies/2012/10/music.owl#Material (MN0000386865) |

Any idea why the symmetric property is not inferred? For Artist #Material (MN0000386865) the query won't find anything.