VIP Benefits can be activated by using a VIP Ticket through the VIP interface (found on the main screen by click the little portrait on the top left). 30 min and 2 hr tickets are not uncommon to find as in-game rewards, although high level tickets need to be bought.
Your VIP level is in no way connected to the time of you VIP ticket however. Instead, the VIP skill goes up only when you buy gems (only through IAPs). The VIP level can currently go up to 10, with the points needed for each level being as follows:
|Level||Points Needed||Total Points Needed|