In SRP, is the client protected from server impersonation?
Yes (and it is an explicit goal of SRP; perhaps not as advertised as such)

The only attack that SRP allows is for the faux server to take a guess at the password, and then attempt to allow the client to login based on that guess (and if the client thinks he succeeds, the guess was correct).

Given that we assume that the password was strong enough to make that unlikely, you're safe.