Competency partners have an unlimited threshold for Visual Studio Online subscriptions and should not need a threshold increase. Action Pack partners can have their Visual Studio Online threshold increased to 360% of their subscription if they contact customer service.
Use the resources below to learn more about increasing an Action Pack threshold to 360%.
Details regarding the Microsoft Partner Network Visual Studio subscriptions
Unable to Assign Visual Studio Online Subscriptions to New Users http://support.microsoft.com/kb/2954371