[pyre]

If Google Apps doesn't know about foo.us, then I think that answer would be no. (Though I would confirm this with someone more knowledgeable)

[pasbesoin]

I haven't used the alias feature, myself, but I believe the grand parent post is asking about a circumstance where your Google Apps account specifically does know about and supports the second domain (as an alias).

[zacharypinter]

Exactly. Thanks for clarifying :)