I don't think he's talking about a bonus as the beginning of the game, but instead the level cap becoming dependent on the original values of the statistic. Like if you start with 20 in charisma you might never breach 90, but if you start with 120 intelligence, you'll probably pass 250.
I would also like to note here that level caps should not be completely solid like the earth ground, but more proportional, like a gas giant. So there isn't any specific number where it tells you "you can't advance farther", just a number where it tells you "it will be hard to advance farther", "it will be very hard to advance farther", or "it will be insanely hard to advance farther", and possibly "it will be soul-crushingly hard to advance farther".