I used this:
config.vm.network :bridged , :mac => "080027XXXXXX"
and got what I wanted.
The docs are unclear on what the syntax for the options hash were, and there seemed to be no example on what this should look like. So, here it is! Bridged with a mac address (edited of course). This brings up eth1 with the mac specified, which makes my DHCP server happy, and gives it a proper fqdn on my network.