A:AnswerYour subscription is tied to your account, regardless of which console you're on. You'll have access to all PS Plus services on both PS4 and PS5.
A:AnswerI don't think it's region free and probably won't work according to the fine print on the digital PS Plus card. This is what it says:
PlayStation Plus is only available to legal U.S., Canada, and Mexico residents (18 years or older) with an SEN account