It's not that clear cut. The OP's question is justified.
Technically there are no salary requirements. However in reality, if the salary is too low this can cause IRCC to question if the individual is really doing a NOC A, B, or 0 job (since they are not being compensated in alignment) or whether they are actually doing a NOC C or D role which of course doesn't count towards CEC. We have seen a number of refusals on this forum for that reason (e.g. IRCC decided that based on salary the individual wasn't really a manager). That's what the OP is concerned about. Generally when you are being paid less than the "low" wage for your NOC in your part of the country you are potentially at risk for this happening.
OP - I don't think there is a clear cut answer to your question unfortunately however ideally your base wage should not be the server wage but higher. You don't say what province or city you are in. Published low end of the wage for this NOC is 13.50 for Canada but may be lower for your region. Any chance they are going to give you a pay increase soon? When you get your experience letter, I would make sure that your employer includes the fact that you were compensated with manager tips. I don't know if this will put you in the clear. There isn't a clear cut answer since a lot of this is up to the individual officer who looks at your application.
