Leticia, we may be related.
My grandfather was Domingo Castellanos Rodríguez, of Limonar, Matanzas. He was born in Las Palmas, Gran Canaria, about 1874, and migrated to Cuba as a young man. He had a brother named Esteban, and their parents were Esteban Castellanos Marrero and Brígida Rodríguez. There were probably other brothers and sisters, but I have no information on them. It may be a coincidence, but one of my uncles was named Guillermo Castellanos.
On page 110 of the book "Guamacaro, biografía de un municipio cubano" there is a list of "los agricultores, colonos y ganaderos más conocidos" of the Canímar area (near Limonar). The list includes Domingo Castellanos, and Waldo Rodríguez Cartaya, among others. A Carlos Cartaya is mentioned on the next page.
Amarillas is a town in the southeast part of Matanzas Province; it is close to Aguada de Pasajeros, which is in Cienfuegos. A hundred years ago, communication between this area and Limonar must have been very difficult, so it is possible that brothers who lived "that far" just lost track of each other.
I will be happy to exchange further information with you. Maybe working together we can find a connection between your Castellanos and mine.