WHO is in charge of Spain’s travel protocol, the regional governments or Madrid? The Balearic government was not so long ago all in favour of using domestic tourism to get the ball rolling - now it appears that it has changed its mind and moved its attention to foreign tourism.
However, while Palma can dictate domestic tourism rules, only Madrid, and to a certain extent other EU countries, can rule on foreign visitors. So, the Balearics has hit the buffers. In the current legal framework, regional authorities may close their own borders to all but essential domestic travel.
But they do not have the ability to deny entry to European travellers through international borders such as airports or ports, which are centrally managed. It is up to the government of Spain to make that decision, but so far it has not done so, with exceptions for a ban on non-essential travel from the United Kingdom and from non-EU countries.
The only condition that was introduced for passengers arriving by air or sea was a PCR test, although this was not required of people entering by land - so, providing travel was permitted by country of origin, EU members have been able to motor into Spain with no checks at all. Take Madrid, every weekend it’s bursting with French party lovers avoiding lockdowns at home. Someone needs to get a grip in Spain.