The Spanish government have nothing to do with it...It's the Thai embassy in Madrid. They will only issue visas for Spanish people or foreigners living there that have a residence ID card. Many Brits live in Spain but don't get the card.. if the guy wants 90 days he needs a 60 days visa which he can extend in Thailand by 30 days. He can't do it 'arse about face'.
Check out Royal Thai Embassy in Madrid. Pretty sure you will need proof of residence in Spain before they will issue you with a Visa. If you can comply with the Visa requirements you can then extend the 60 days in Thailand for a further 30 days,as Robert has already explained.
Johan...if nothing has changed since your last report.... Check very carefully the information that you submitted. If you have a typo error...it will be rejected. If you have any changes...eg stayed in a hotel overnight...in country...it will be rejected.
OK... So landlord's cannot have an agent. Unless they give them a power of attorney. And the agent has then got to give the renter a power of attorney. They (Phuket) want original documents... not copies or scans. I'm sure this is just a Phuket 'thing'...of course I am requesting a new rental agreement from the actual owner and a signed power of attorney...I don't want to be running to Phuket 2 or 3 times at 800 baht taxi fare each time. They don't make it easy, however long you have been here!