Both will work but be more patient with the top dressing.

kathaab, you are ready for the Compost, Soil and Mulch forum. Don't be intimidated by their technical sounding talk.

My gardening mission is to attract earthworms. I both incorporate organic matter---mostly my own compost---and put it on top. Both approaches work well. Worms love seaweed, newspaper, hay, straw, leaves. I gather those ingredients and apply them quite liberally to the surface of my gardens.