Well Kotlin isn't even officially released yet (1.0 candidate came out last week) so no company is probably using it for production yet.
I don't think one can make any pronouncement about Kotlin's success or failures for several years.
This will of course improve for Kotlin, specially if they get some Google blessing.
EDIT: Also forgot to mention that on Swift's case, it is a first class language being pushed by the platform's owner, not a 2nd class language without any kind of consideration from the platform SDK.