Your school needs to nominate you for these scholarships-- they're allowed to nominate the equivalent of 2% of the graduating class. Once you have the nomination you can apply for the scholarship itself (in the application there will be a place for your counsellor/principal to sign acknowledging the nomination). In general I think being nominated for major scholarships, even if you don't receive them, reflects your chances of acceptance (simply because if your school thinks you're worth the money, UBC will appreciate that, but it certainly isn't a rule). So yes you apply before you know whether or not you're accepted, but if you're a candidate in the running for one of these scholarships I see no reason why you wouldn't be accepted into the school. Hope that helps! :)