What determines the length of time between ante increases in No Limit Hold-em on the WPT?

Answer 1

In tournaments, the blinds go up every X minutes. In many single day tournaments in AC or Vegas, the blinds go up every 20 minutes. In bigger tournaments it is usually 30 minutes or more. The world series of poker has 2 hour levels

I would assume most WPT events probably have 30 minute or 60 minute levels

Answer 2

All tournament games have a set time before the increase it will be down to the operator of the tourney to set the time.