With only 3 PHP jobs as it stands in Bilbao, it might be worthwhile to check out job offers in similar fields of expertise. Why not check out the most dominant categories of Programmer and Technician, that the range of jobs can be broken down to. Jobs that require MySQL, Symfony, or WordPress are often seen in job offers in this area.
This is not the best time to search for PHP internship positions. Corporations are now almost exclusively seeking qualified aspiring pros. Although startups are a rising trend, there aren't any currently advertising for PHP. Use the region map at the top of the page to see where the offices are located.