Would you happen to know also the bus company offering the Zihuatanejo route to Puerto Escondido?
Answer Dear 905… Yes, you are correct that you will need to go from Punta Mita to Puerto Vallarta to begin your trip to Zihuatanejo. Although this is a long trip, I do not see why it would have to be overnight unless you want it that way. You will probably have several options of getting from Punta Mita to the main bus terminal in Puerto Vallarta. Pacifico bus lines run with great frequency up and down Highway 200. You will need to catch a collectivo out to the highway from Punta Mita. While you are in Punta Mita, you may discover that there are collectivos that will take you all the way into the terminal in Puerto Vallarta without having to take the Pacifico bus. My guess is that a taxi for this trip would cost about 400 Pesos. Once at the main terminal, if you have not prearranged and bought a ticket, you will probably have more than one choice of bus lines. Groupo Estrella Blanca looks like a good choice. They have a website but it looks to be under construction at this time. WWW.