There are people who have face-blindness (inability to discern faces) or dyslexia (visual processing disorder that leads to severe difficulties with reading). The two aren't strongly correlated.

Dyslexia seems to be tied to some broader visual processing issues, which impair the ability to discriminate faces somewhat. But not the other way around.

If the two skills were strongly related, you'd expect a very strong and obvious link. Maybe in form of both performing poorly, if damage to the same pathways impairs both. Or as one performing poorly while another performs unusually well (super-recognizers? children who learn reading at 2?) - if the two skills compete for brain real estate and create a performance tradeoff, as claimed.