In a small saucepan, toast the pine nuts over moderate heat, shaking the pan a few times, until the nuts are fragrant, about 1 minute. Transfer to a plate.
Add the clam juice to the saucepan and boil over high heat until reduced by half, about 5 minutes. Add the wine and boil until reduced to 1/4 cup, about 5 minutes. Add the shallot, thyme and marjoram and season with salt and pepper. Cover the sauce and keep warm.
Light a grill. Rub the fish fillets with olive oil and season with salt and pepper. Grill over high heat, turning once, until nicely charred and just cooked through, about 3 minutes per side. Transfer the fish to plates.
Stir the parsley into the wine sauce. Coarsely chop the toasted pine nuts. Spoon the sauce over the fish, sprinkle with the pine nuts and serve.