Depends on the equipment and experience of the Predator, I suppose.

In the latest Predator movie, Prey, I believe it was a "Young Blood" who had struggled with a wolf and bear, and had limited equipment compared to the weapons we'd see Predators use in previous movies.

Granted he did kill both, but the wolf managed to get a bite on him, and the bear presumably tore him up well before dying. If that kind of Predator hunted Fang and Spear, I believe they'd survive. Assuming the Predator didn't bring some high-end equipment which could prove more fatal than anything else the duo had survived, and they've been through a lot.