The nature of the interface between the components of a nanocomposite is a major determining factor in the resulting properties. Using a graphene-mesoporous germanium nanocomposite with a core-shell structure as a template for complex graphene-based nanocomposites, an approach to quantify the interactions between the graphene coating and the component materials is proposed. By monitoring the pressure-induced shift of the Raman G-peak, the degree of coupling between the components, a parameter that is critical in determining the properties of a nanocomposite, can be evaluated. In addition, pressure-induced transformations are a way to tune the physical and chemical properties of materials, and this method provides an opportunity for the controlled design of nanocomposites.