Heat oil in a nonstick skillet over high heat and cook bacon until crisp, about 5 minutes. Remove bacon and drain on a plate lined with paper towels.
Pour off most of the bacon grease. Cook onions in the remaining grease until soft and translucent, about 5 minutes. Add artichokes and season with salt and pepper. Cook and stir for 3 to 5 minutes. Pour some white wine into the skillet every few minutes and simmer until artichokes are soft, about 15 minutes. Season with dill and remove from heat. Let cool completely.
Combine bacon, artichoke mixture, and ricotta cheese in a blender; blend until smooth. Season filling with salt and pepper.
Unroll puff pastry sheet on a flat surface. Cover evenly with the artichoke mixture, leaving 1 inch bare on one of the longer edges. Tightly roll up sheet lengthwise, towards the bare edge, and press ends tightly together. Wrap in plastic wrap and cool in refrigerator for at least 1 hour and up to 24 hours.
Preheat the oven to 400 degrees F (200 degrees C). Line a baking sheet with parchment paper.
Slice stuffed pastry log into 3/4-inch slices so you have 16 to 22 pinwheels. Arrange pinwheels on the baking sheet in the shape of a Christmas tree; start with 6 rolls next to each other (or 5 if you only have 16), then continue with shorter rows. Place the last pinwheel on the bottom as the tree trunk. Brush beaten egg yolk onto pinwheels.
Bake in the preheated oven until puffed up and golden, 20 to 25 minutes. Remove from oven. Decorate with cherry tomato 'Christmas ornaments'.
