They should have spelled it Plinny if they expected us to know how to pronounce it. I'd heard of Pliny the Elder (and Younger) before the beer(s), but I still didn't know how it was supposed to be pronounced. I go back and forth, sometimes it's Pliny, other times Plinny.
But it's Vinnie's beer, he can pronounce it any way he wants regardless of the historical pronunciation.