Transactions are being enlisted as XAResources with recovery disabled by default.
XAResource enlistment without recovery does not bring any benefit over Synchronization enlistment, which is more efficient(30-40%). See http://infinispan.blogspot.com/2011/06/transactions-enhancements-in-50.html
So the suggested enlistment should be Synchronization (default). Also if xa-enlistment is preferred then recovery should be enabled by default - there's little reason in using XAResource enlistment without recovery.