There are none in Salou. There are stables out in Vilafortuny but are used for Flamenco shows so not a school. Try below... other than that I think you will have to go a long way out to find one. http://lemanoir.wix.com/hipica-pre/inicio
here are the details for Westfork on the main road from Salou to Reus.They speak good English so give them a call.
All rides accompanied. Riding lessons available. Fantastic country site on 10.000 m2. Bar with covered terrace, toilets, track for beginners, independent area for fillies, tennis court, playground, etc.Kids camps available.