The access to Enterprise Architect model properties can be done via the class PropertiesManager.
Model umlModel = ...
Map options = ...
umlModel.read("Enterprise Architect Application", options);
List<com.sodius.mdw.metamodel.uml21.Model> models = umlModel.<com.sodius.mdw.metamodel.uml21.Model> getInstances(UMLPackage.Literals.MODEL);
String eaVersion = null;
for (com.sodius.mdw.metamodel.uml21.Model model : models) {
eaVersion = PropertiesManager.getEAVersion(model);
if (eaVersion != null)
break;
}
}

Reading UML Data
Reading Enterprise Architect Data
MDAccess for UML API Reference
MDAccess for Enterprise Architect API Reference