De acordo com esta entrada do fórum JBoss nenhum:Por que meu driver compatível com JDBC4 está carregado como "não compatível com JDBC" ?
E código fonte:
/**
* Report whether the driver is a genuine JDBC compliant driver. A
* driver may only report "true" here if it passes the JDBC compliance
* tests, otherwise it is required to return false. JDBC compliance
* requires full support for the JDBC API and full support for SQL 92
* Entry Level.
*
* <p>For PostgreSQL, this is not yet possible, as we are not SQL92
* compliant (yet).
*/
public boolean jdbcCompliant()
{
return false;
}
https://github.com/pgjdbc/pgjdbc /blob/REL9_3_1102/org/postgresql/Driver.java.in
Isso faz parte da lista de tarefas http://jdbc.postgresql.org/development/ todo.html#Compliance
