Under section 9 of the Schedule in the Residential Tenancy Regulation, the landlord cannot unreasonably restrict a tenants guests from entering the tenants rental property or charge you a fee for having guests visit you even if they stay overnight.
However if the guest stays longer than one night then the landlord could restrict that guest from staying longer if it's in the lease.
Read your lease and Terms and Conditions very carefully to see what the landlord states as rules and regulations in the lease.