Which is most important to you – a world-class school or a school that qualifies as an accredited institution for the purpose of code section 529? I’m not a barre expert, nor do I know the IRS definition of accredited institution within that particular code section (I’m a former tax accountant but I did corporate, not individual, tax).
Your first step might be to research barre certification courses to find out which are the best recognized in your area as it meets your definition of “world class.” Then ask them about their programs. You might have to explain “accredited institution” to them to see if they fall within the IRS definition for use of your 529 funds.
Best of luck to you!