Hello,
Similar to the UCSm, when you are defining a boot policy for SAN, the target is going to differ depending on each configured boot order. This will extend to central in that you can define a different one for each suborg and apply them in that manner.
However, there is no current method of implementing a "vlan alias" type Boot policy where you only define one but its definition changes depending on the domain. Each new set of targets you wish to define will need to exist within it's own policy.
Regards,
-Gabriel