MetaMatrix is Redhat supported product, so Yes there is Hibernate dialect available for MetaMatrix.
However, Teiid does not have one yet, you can track the progress at https://jira.jboss.org/jira/browse/TEIID-416
As per using in the Seam, it should exactly same as using any other JDBC Source.
Thanks. I did mean to ask about a dialect for Teiid. Thanks for the Jira link - I will track progress there.