I have 2 iphones, does the Cloud cover both iphones?

If both iPhones are using the same Apple ID / iCloud account, then the iCloud storage will be available to both.

If not, you would need to use Family sharing to share the iCloud Storage between the 2 Apple IDs, and it would then be available to all devices signed in to those Apple IDs.

I have 2 iPhones, does the Cloud subscription I have cover both iPhones?

Yes, sure.

No