In the past the answer was no. However, with current versions of Postfix, you can create regular expression maps and include a wildcard when an address at all domains should go to a single mailbox. For example, if you have several virtual alias domains, you can create entries like the following in main.cf:
virtual_alias_domains = example.com, oreilly.com, ora.com virtual_alias_maps = regexp:/etc/postfix/virtual_alias
And in /etc/postfix/virtual_alias include an entry like this:
/postmaster@.*/ admin@seaglass.com
Then all mail for postmaster@example.com, postmaster@oreilly.com, and postmaster@ora.com will go to admin@seaglass.com.
If any of your virtual alias domains requires a different alias mapping, then this shortcut won't work. You will need a separate entry for each domain. With a script or makefile this is a very simple thing to maintain.