Bonus languages for high INT mod have to be chosen from a small list for your race. When there is no list given I asume that the list has 0 extra languages to chose from. So the INT mod is wasted bonus language wise.
As a part of the Advance Template, a creature gains +4 Intelligence. I know that this grants extra skill points and I know how to determine what skills are Class Skills for various creatures, but does this increase also grant a creature added languages? Other than races without racial hit dice (such as most player characters), there doesn't seem to be a strict rule regarding how many languages a creature speaks.
Are you referring to the bonus starting language or languages in general?
Here's the rule around bonus language:
"The number of bonus languages your character knows at
the start of the game." (Page 17 Core rule book)
You could always use the extra skill points and put ranks in Linguistics since that's how you pick up languages beyond your starting bonus language.
Advanced template is what I would consider a inherited template, so you could give that creature bonus starting languages. What would be appropriate would be based on the nature of the creature you're templating.