<persistence-unit>
<!-- no jta-datasource defined -->
</persistence-unt>

and

<persistence-unit transaction-type="RESOURCE_LOCAL">
<!-- no jta-datasource defined -->
</persistence-unt>

Seems to fail with
WARN [ServiceController] Problem starting service persistence.units:ear=jblogApp.ear,jar=jblogBeans.jar,unitName=jblog
java.lang.RuntimeException: You have not defined a jta-data-source for a JTA enabled persistence context named: jblog

(2) should work
(1) is very much expected from a usability POV. basically, if no jta-datasource is defined, we should expect a default transaction-type of RESOURCE_LOCAL

Note that you might want to let the persistence provider test such compatibility issues, since it has more contextual information than the container (ie knows the meaning of the proprietary properties)

Max can you confirm that my description match your bug.