Cognitive computing applications are steadily growing across sectors and increasingly considered for adoption in government for transforming public services. Semantic technologies have been identified as one of the enabling technologies for cognitive computing capabilities. This paper describes some foundational efforts for the deployment of ontological semantics-driven cognitive capabilities in delivering a family of public services. First, we present an application profile for the Core Public Service Vocabulary extending the core vocabulary into a rich domain ontology – Social Welfare Service Ontology. Second, we use the Social Welfare Service domain ontology to as a basis for the design of a Linked Public Service Cloud. The proposed Cloud comprises a detailed description of concrete instances of social welfare services and links (relationship) between such services. By linking services across linked public service clouds associated with different public administrations, like different municipal governments, we demonstrate how cognitive capabilities supporting citizen requests could be realized through reasoning and propagation of information over semantic networks of public service clouds.