Yes, provided the treaty nationality is traceable through it. A company can hold the investment where at least fifty per cent of its ownership belongs to nationals of the treaty country, and Canadian citizenship of the individual shareholders is what supplies that. Permanent residence in Canada does not.
Nationality follows the shares upward
Buyers often assume the analysis stops at the place of incorporation, so a corporation registered in Ontario feels Canadian enough. It is not the incorporation that matters but who owns the shares, and where the immediate owner is itself a company the enquiry continues upward until it reaches individuals. The enterprise in the United States must be at least half owned by nationals of the treaty country, and the individual investor whose visa is sought must hold that nationality too.
Two Canadian citizens holding all the shares of the Ontario company, which in turn holds the American company, satisfy the requirement, and the chain should be documented with both registers and, where relevant, a shareholders agreement. Two points regularly cause trouble. A spouse or partner who holds Canadian permanent residence rather than citizenship does not contribute treaty nationality, and their shares count on the wrong side of the calculation.
Second, later share issuances can dilute the chain, so the position at the time of application is what counts, not the position when the structure was designed.