I do not see why the question of "who do you serve" has caused such uproar from Efstratios.

It seems he is still officially sworn to Anastasios. But conversations that have been overheard in the inn where House Tapeki is headquartered are interesting. (OOC: Peverpink made clear that the inn is open to all so I see no problem using posts in there as IC knowledge)

My guess is that Efstratios is staying loyal to Asteri just long enough to get Durazzo. Then he will turn and hand over the province to House Tapeki so that House finally has some land.