I've been researching the best way to get from Porto to Santiago de Compostela. Thought there would be a train, but the only way to go by train seems to be to change in Vigo with not many departure options. Somewhere I read that there is a bus that goes all the way from Porto to Santiago, departing from the Porto airport. I also read that when a traveler checked it out, no one at the bus office at the Porto Airport even knew for certain if there was a direct bus, but one did arrive and the driver said it was indeed going to Santiago. Does anyone know the best option, and best website to check departure/arrival times?
There are two direct buses a day from the airport with http://www.alsa.es/compra-y-horarios/internacionales/?searchType=international
I do not know any other permutations without doing the same amount of research that you have, presumably correctly, performed.
Your understanding is correct that the train schedule is minimal, requiring connections and patience. Bus companies serving Porto each have their own mini-station, not a central, shared bus station. On p. 303 of Rick's Portugal book, the regular bus by Internorte is suggested, but does not run daily (6x/week summer and 4x/week winter). Or consider the "expensive but convenient" all-day bus tour from www.portotours.com (98-120 euros, departs Port 8:00), and you need not bother returning to Porto with them.