If you are new to hibernate-maven-plugin, in many cases, the Configuration-Method-Precedence may be the source of configuration errors. To solve this problem, you should run maven with the debugging output enabled. For example, by executing:
mvn -X compile hibernate:create
(The compile might be necessary, because hibernate-maven-plugin has to scan the compiled classes for annotations!)
Unlike the majority of the maven-plugins, hibernate-maven-plugin was designed to give a good many hints, when debugging is enabled. Because, if you do not know, what went wrong, you can't fix it!
But be warned: hibernate-maven-plugin tends to be very chatty ;)