Methods and apparatus for data aggregation and multiplexing of one or more virtual bus interfaces via a physical bus interface. Various disclosed embodiments are configured to: (i) multiplex multiple logical interfaces over a single physical interface, (ii) exchange session management and logical interface control, (iii) manage flow control, (iv) provide “hints” about the data (e.g., metadata), and/or (v) pad data packets. In one particular implementation, the methods and apparatus are configured for use within a wireless-enabled portable electronic device, such as for example a cellular-enabled smartphone, and make use of one or more features of a high-speed serialized physical bus interface.