This is how they present to the world on their website...
Western Australia's Leading Regional Airline - Skywest Airlines
Down the bottom of the page you will find this...
© Virgin Australia Regional Airlines Pty Ltd ABN 76 008 997 662
What would be the commercial advantage for JB to "merge" the operations? The cost benefits come from back room functions such as purchasing as a group, keep the workforce fragmented and AOCs separate to keep DOCs low.