A handful of them are used to participate in certain hunts. The Common Hunting Trophies, Jaspilite Iron, Liontail Nytha Spines, and Nomad's Charm come to mind. ^^ Otherwise they aren't used for a whole lot yet, but we anticipate more uses will be added in the future!
Wild wolves are notoriously difficult to befriend, it's meant to be a real treat to find them. There isn't a particular area of the campaign that seems to have "better" chances of encountering them (though of course, they only show up in the sword areas of each region, not the beginning areas).
Through my own experience, I'd say having a level 10 wolf + companion and exploring as quickly as possible is the only real way to increase your chances. This guide is a little older now, but still has some really good info, if you haven't looked already!
