here's another update for spain and for the balearics and ibiza especially.
as of today, people arriving on international flights (or ferries that originated outside of spain) have to show a negative PCR covid test which was made 72hrs or less before departure in the country of origin. important detail: the text of the test has to be either in spanish or in english - other languages are NOT accepted currently. if you fail to bring a test and they check you, an antigen rapid test will be made at the airport. this won't be free though - you'll have to pay a penalty fee (details to follow, I think in the first few days they might not fine you for it). I also heard that currently they don't check everybody, but use an aleatoric system.
currently, people travelling from the mainland to the balearics (either via domestic flight or ferry) don't have to bring a test - but this is something the balearic government wants to change and thus might change over the course of the next months. also, for next summer,the balearic govt wants to pay for the antigen tests on arrival so that you don't get fined if you arrive without a negative PCR test. mind, this is still half a year away and if the good vaccine news continue, there's hoping the vulnerable will be immunized until then and if so, the entire testing strategy might change again.
the corona situation on the balearics is currently stable and improving slowly but steadily. the fourteen day incidence per 100k people has now gone down to 200 while lots of places on the mainland are still on double that figure. but overall, the situation in the entire country is getting better.
for those interested in detail numbers, follow these two guys on twitter for balearics and ibiza numbers: @fcotienda and @druizaguilera. they both produce daily stats. and for spain in general, check this page
https://www.mscbs.gob.es/profesionales/saludPublica/ccayes/alertasActual/nCov/situacionActual.htm , further below, the second link under 'resumen de la situación, called 'actualización...' gets updated daily mon-fri at around 7pm CET and gives lots of detail numbers for the country and the autonomías.