Can a Grade 7 student play on a Grade 8 (bantam) team?

Only as an exemption. A Grade 7 student may play on a Grade 8 team only when the member school would otherwise be unable to field that team because of insufficient numbers. Submit the Grade 7 Eligibility Application Form (handbook 817.0) to the Eligibility Officer. Grade 7 students cannot play on junior or senior teams.

Sources: https://www.bcschoolsports.ca/member-services/student-athlete-eligibility, https://www.bcschoolsports.ca/quick-guide and https://www.bcschoolsports.ca/about-us/faq