Vince, La Coruna is a wonderful city to explore, and, for me, it is a shame to stay out by the airport, which is a long way from the city.
I do not think that La Poetisa is walkable from the airport (and, even if it was, I do you really want to walk it post midnight), so you need a taxi to the hotel anyway (as the airport buses are finished by the time the Vueling plane lands). You then needanother taxi either back to the airport next day (to then catch the airport bus into the city), or a taxi into the city next day.
There are plenty of cheap hotels in La Coruna, and unless you are going to walk to Neda / Xaron next day from Ferrol, you have a down day before you start the Ingles. You should also be aware that there isn't a train from La Coruna to Ferrol between 08.57 and 14.31.
Think about instead taking a taxi from the airport and staying either near the station, as Faith suggests, or, because the station isn't near the centre either, a hotel nearer the centre, spend the morning exploring La Coruna, and then either catching the 14.31 or 17.20 train to Ferrol. The bus network in La Coruna is cheap and frequent to get around.
If you are flying into La Coruna, at least give yourself every chance to explore it. La Coruna, as a city, for me, was far more interesting than Santiago. You will not regret - the Tower of Hercules, Moore's tomb and the Riazor were all big highlights for me to see before I went off to Ferrol.