The README.md file does not contain all steps that are needed to turn the JTS transactions on in JBoss EAP 6.x. Below are the complete steps:
/subsystem=jacorb:write-attribute(name=transactions,value="on") /subsystem=jacorb:write-attribute(name="name",value="${jboss.node.name}") /subsystem=jacorb:write-attribute(name="root-context",value="${jboss.node.name}/Naming/root") /subsystem=transactions:write-attribute(name=jts,value=true) /subsystem=transactions:write-attribute(name=node-identifier,value="${jboss.tx.node.id}")