The service providers to the locations you are asking about are listed here. There are other service providers to other locations along your route. Usually the best way to find them is to look for the bus station website or the town council website where there is often a bus schedule posted. Renex and Rede Express have a comprehensive bus network that covers much of Portugal and CP covers a lot with its rail network.
1910
Tui
ALSA has one bus per day north and south between Santiago and Lisboa that stops at Tuy. This is an international schedule.
http://www.alsa.es/
ATSA (not ALSA) provides several buses daily between Tui and Vigo.
Vigo Bus Station ... See ATSA.
http://vigobus.com/
Renfe provides service Vigo to Valenca Portugal with a stop in Tui.
Renfe
http://www.renfe.com/
Castromil (Monbus) connects Tui to Pontevedra and Pontevedra to Santiago (two stages).
http://www.monbus.es/index2.htm
3300
Santiago to Porto and Lisboa
3301 This section describes transportation options from Santiago to Porto and Lisboa
Index 3300
3302 Planes
3302 Trains
3303 Buses
3301
Planes
There are flights from A Coruña to Lisboa.
A Coruña Airport (LCG)
http://www.aena-aeropuertos.es/csee/Satellite/Aeropuerto-A-Coruna/en/
3302
Trains
Renfe operates trains from Santiago to Vigo and from Vigo to Valenca.
CP Celta operates trains from Vigo to Porto.
CP operates regional and national trains from Valenca to Porto and Porto to Lisboa. Station Gare do Oriente is closest to Lisboa airport.
Renfe
http://www.renfe.com/
Comboios de Portugal (CP) (urban, regional, national, and international train services)
http://www.cp.pt/cp/displayPage.do?vgnextoid=87cbd5abe2a74010VgnVCM1000007b01a8c0RCRD
3303
Buses
Note: there is no central bus station in Porto.
ALSA operates one bus daily from Santiago bus station to Porto and Lisboa. The bus stops at Porto Airport and Porto Metro Station Casa da Musica. The bus stops at Lisboa Gare do Oriente and Lisboa Gare Sete Rio.
Monbus provides bus service from Santiago bus station to Vigo bus station.
Autna provides bus service from Vigo bus station to Porto.
Autna has bus stops in Porto at the following locations from South to North:
a. Campo Mártires da Patria, 37
The closest Metro is Estação Sao Bento line D
b. Avda. de los Aliados – McDonald’s
The closest Metro is Estação Sao Bento line D
c. Aeropuerto
Metro line E
Renex operates buses from Porto to Lisboa.
Renex bus stop in Porto is located at Campo Mártires da Patria, 37. The closest Metro is Estação Sao Bento line D.
In Lisboa, Renex operates buses from Gare do Oriente which is co-located with the train station and is the closest station to the airport.
Rede Expressos operates buses from Porto to Lisboa.
Rede Expresso point of sale (and bus stop) in Porto is located Garagem Atlantico Rua Alexandre Herculano, 366 4000 Porto. The closest Metro is Estação Sao Bento line D.
In Lisboa, Rede Expressos operates buses from from Sete Rios bus station.
ALSA
http://www.alsa.es/
Monbus
http://www.monbus.es/index2.htm
Autna
http://www.autna.com/es/
Renex
http://www.renex.pt/
Rede Expressos
http://www.rede-expressos.pt/