I used to raise Bishons and I think it looks like one to me.
If he is about 6 months he about grown. Probably won't grow much more. 25 lbs is pretty big for a Bishon tho. If it is a cross of poodle and maltese it may be a standard poodle cross. A mininture poodle and a maltese probably wouldn't weigh much over 10-12 pounds.