It is possible that a site with two domains can get an ODP listing. It is possible (but not likely) that the mere presence of the two domains may make either one unlistable.
The ODP submittal policy describes what would happen if you SUBMITTED both domains: the kicker is, that could happen if the domains were not well linked together (that is, it appeared that the connection between them was being deceptively concealed), even if it was not the webmaster who was abusively suggesting the second domain.
We don't care how many domains a website is spread over (it would be eligible for only one submittal, no matter how many domains there were.) We do care about people giving honest information about the entity that is represented by the website.
And...the vast majority of people pushing for multiple listings are not eligible for even one listing. So honest people will be very careful not to even look like that's what they're doing.
