I updated a few features to the cxf client plugin.  I added the following new config parameters to help drive the wsdl2java script.

namespace = [package name to use for generated classes] //optional – uses packages from wsdl if not provided client = [true or false] //optional – used to tell wsdl2java to output sample clients, usually not needed – defaults to false binding = [Specifies JAXWS or JAXB binding files or XMLBeans context files] //optional outputDir = [location to output generated files] //optional – defaults to src/java

You can get more details at https://github.com/Grails-Plugin-Consortium/grails-cxf-client