The law in Spain and most EEC Countries requires the following licence and minimum age limits:-

50cc aged 17 or over with Full motorbike or car license

125cc aged 18 or over with Full motorbike or car license

Mountain Bike and Fun Bikes, no age limit to ride but contract of hire must be signed by someone aged 16 and over  

I-LoveBike require your passport and a deposit of:- 300Euro for 50cc and 125cc hire and 50Euro for mountain and fun bike hire