You should use model of Seam facet instead of Seam wizard:
...
Set<Action> actions = wizard.getFacetedProjectWorkingCopy().getProjectFacetActions();
for (Action action : actions) {
if(ISeamFacetDataModelProperties.SEAM_FACET_ID.equals(action.getProjectFacetVersion().getProjectFacet().getId())) {
IDataModel seamFacetModel = (IDataModel)action.getConfig();
ejbProjectName = seamFacetModel.getStringProperty(ISeamFacetDataModelProperties.SEAM_EJB_PROJECT);
break;
}
}