I believe that children with (drinking age) parents are (legally) allowed into any establishment here (Ontario, Canada) with a liquor license -- think "restaurant".

It's different in the US. I think it even differs from state to state. But around here, if it's a genuine bar or pub, then no one under 21 is allowed. If it's a restaurant that happens to serve alcohol, then of course the kids are allowed in. But if it's just a bar, then no kids.