Ok, I figured this out. Here is the configuration that made it working:
<bindings version="2.1"
xmlns="http://java.sun.com/xml/ns/jaxb"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
xmlns:simplify="http://jaxb2-commons.dev.java.net/basic/simplify"
extensionBindingPrefixes="simplify">
<bindings schemaLocation="../wsdl/messages.xsd" node="/xs:schema/xs:complexType[@name='ArrayOfResponseMessagesType']/xs:choice/xs:element[1]">
<simplify:as-element-property/>
</bindings>
</bindings>
That simple.