Tomatoes can be frozen whole in freezer ziploc bags. When ready use them for any cooked dish and not as a fresh tomato. Here are some helpful suggestions/ tips for freezing tomatoes.
Cut an X (only skin deep!) in the rounded side of the tomato before freezing. Then when taken out frozen it is very simple to peel away the skin.
Cut tomatoes in half, season with olive oil, salt, pepper and grill over high heat. When done and cool, bag and freeze. You will keep some of the grilled flavour adding to your prepared dish.