There's no wind guarantee in Barcelona at this time of the year (well, there's little guarantee in general in this area). If you are willing to travel 250 km north, you have Leucate where there's more chance to have wind but those winds are very strong and gusty (usually around 30-40 kts) and the water temparature is already very cold.
There are options for snowkiting - if there is snow in the mountains - but you would probably have to travel maybe 100-150 km. I don't snowkite, so you may want to wait for someone better informed to answer or you can ask directly on
http://www.spainkiters.com (Cataluña). If you don't speak spanish, some of those guys speak english.
Enjoy!
Steph