The short answer is no - see [TEIID-3439] Add support for aliases with . - JBoss Issue Tracker
It turns out to be pretty thorny to support based upon a lot of early MetaMatrix assumptions that were made about column naming and qualification - starting in the parser which then worked it's way through the code.
Ok, so at least it's not me
Of course I can work around this, and I know there are bigger issues.
It would be nice to have, but it's not a show stopper.