Two model analyses are constructed in order to determine the influence of bonding materials on the propagation of electromagnetic waves in otherwise bilaminated composites. The geometric arrangement of the composite with the bond is treated as a special type of a trilaminated composite in which each of its major constituents is sandwiched between two bonding layers. In the first model, a recently developed continuum mixture theory of electromagnetic wave propagation in bilaminated composites is extended to treat the trilaminated composite. Here, details of the propagation process in the major components and also in the bonding layers are derived. In the second model, the entire effect of the bonds is treated as a modifier to interfacial continuity conditions. In this model the details of the propagation process in the bonding material are ignored. It is found that the results of both models correlate well with each other and also with some exact solutions for a rather wide range of frequencies.