"Can we apply the ideas of The Society of the Spectacle to the Facebook era?"
Yes.
It's not accurate that Debord was talking only about people being influenced by print magazines and printed advertising. The critique is far more profound than that. On particular communications media, also be aware that thesis 172 of Society of the Spectacle contains a clear reference to television:
The same collective isolation prevails even within the family cell, where the omnipresent receivers of spectacular messages fill the isolation with the dominant images — images that derive their full power precisely from that isolation. [emphasis added]
In the same thesis, he also writes:
But the general trend toward isolation, which is the underlying essence of urbanism, must also include a controlled reintegration of the workers in accordance with the planned needs of production and consumption. This reintegration into the system means bringing isolated individuals together as isolated individuals. Factories, cultural centers, tourist resorts and housing developments are specifically designed to foster this type of pseudo-community. [emphasis in bold added]
Next year, 2017, will be 50 years after the book was published (1967), which is a full half of the 100 years that separated it from the first volume of Marx's Capital (1867), and we cannot expect to read it as a crystal ball where technologies are concerned. But it seems to me that the notions of the reintegration and pseudo-community of the isolated and alienated, the pseudo-activity of the passive, fit Facebook, "social media" and the widespread use of mobile phones very well indeed.