Jonathan My questions are if that card can only be used in those countries since I am in Spain ?
As indicated above, all bunq cards generally can be used world-wide. However, acceptance at merchants might vary. Regardless of debit or credit card, all bunq cards will work for you just like debit cards. So there's no reason to go with the Maestro card over Mastercard if you do not live in The Netherlands.
Can the free savings account have a debit card linked to it?
If you're referring to the Easy Savings plan, then no, it's not a bank account for payments. If you want a card to use with your account and use your account for regular payments, you need to upgrade to the Easy Bank plan.
And if I add the debit card will that have a subscription cost ?
The Easy Bank plan includes one (1) free card of your choice. I wouldn't recommend getting the Maestro card if you're from Spain, though. Just get the Mastercard (it works 100% like a debit card for you).