All of the pinto markings are dominant, meaning, if they are present in hetero or homozygous form, they will show (however minimally). As evidenced by some of the horses on here, they can show in as little form as a star on the forehead, or even some tiny dot on the underside of the horse that you'll never see. If sire and dam are both heterozygous for each or any pinto gene, there is a 25% chance that there each offspring will be born without that particular gene. IE, tobiano
If sire and dam are each heterozygous for tobiano, they have a 25% chance of producing a homozygous tobiano foal (TT), 50% of heterozygous (Tt) and 25% of non-tobiano (tt).
*edit, Punnett squares are hard to reproduce on here!*
This is true for each type of pinto gene they carry seperately, and each gene is not dependant on or connected to the others. If your resulting foal ended up tt (or recessive for any of the other pinto genes), he will not produce pinto foals unless bred to a pinto mare. If he is heterozygous (Tt) he will have the same possibilities as his sire, if homozygous (TT) he will always produce pinto. The only way to know for sure since your horse does not APPEAR to be pinto (based on markings) is to have the genetic tests done to see if he's a minimally expressed pinto.