System-on-chip communication architectures have a significant impact on the performance and power consumption of modern multi-processor system-on-chips (MPSoCs). However, customization of such architectures for an application requires the exploration of a large design space. Thus designers need tools to rapidly explore and evaluate relevant communication architecture configurations exhibiting diverse power and performance characteristics. In this paper we present an automated framework for fast system-level, application-specific, power-performance trade-offs in bus matrix communication architecture synthesis. Our paper makes two specific contributions. First, we develop energy macro-models for system-level exploration of bus matrix communication architectures. Second, we incorporate these macro-models into a bus matrix synthesis flow that enables designers to efficiently explore the power-performance design space of different bus matrix configurations. Experimental results show that our energy macro-models incur less than 5% average absolute error compared to gate-level models. Furthermore, our bus matrix synthesis framework generates a tradeoff space with designs that exhibits an approximately 20% variation in power and 40% variation in performance on an industrial networking MPSoC application, demonstrating the utility of our approach.