Bit of an odd idea, but maybe sacrifice one or two tulip leaves next year to turn them into an anti-rabbit spray? Stick it in a blender with some water and horticultural oil so it sticks, and spray it on the plants that get nommed. Maybe toss a garlic clove in there for good measure. There's obviously something the rabbits don't like about the tulips you're growing, so it's worth a shot anyway.

As a note, thank you for using grape hyacinth's proper name -- I didn't know what you were talking about until I looked it up. "Muscari" is much prettier than "grape hyacinth" anyway, imo!