Hello,
Yes, if you create the VLAN 3 in both domains and also allow the VLAN 3 on the trunk interconnecting these two domains then the VLAN 3 will span both domains and will be fully functional.
The only caveat to watch out for is that if you are using VTP Pruning then you must declare the VLAN 3 on the trunk between the two VTP domains as ineligible for pruning. The reason is that the VTP Join messages sent from either side of a trunk will be ignored on the other end because of the VTP domain name mismatch, thus no information about used/unused VLANs will be accepted by either switch, and as a result, all VLANs will be pruned off this trunk. Therefore it is necessary to force the VTP Pruning to leave the VLAN 3 alive on this trunk.
Best regards,
Peter