Heat 2 tablespoons oil in a large, high-sided ovenproof skillet over medium-high. Add fennel wedges, cut side down; cook, undisturbed, until bottoms are golden brown and softened, about 5 minutes. Turn fennel wedges so other cut sides are down; cook, undisturbed, 2 minutes. Scatter tomato mixture around fennel in skillet; add wine. Remove from heat, and arrange cod on top of mixture.