It should be no different between h:commandLink and a4j:commandLink from this point. So, look around.
I wouldn't do it with h:commandLink because it moves off the page. a4j:commandLink is designed for requests, which will be served by the same jsf page. I would expect a4j:commandListener to be able to access methods of the backing bean with request scope.
I found it to be a part of the bigger problem. I cannot get requestmaps as well. I'm still using a basic default installation. Would I be missing something important?