Canada taxation when company pays for travel fees of employee's spouse

[pwang]

Hi,

if a company pays for the travel fees of an employee's spouse (to accompany the spouse to a company-paid business trip), how it is taxed?
Is it taxed as revenue for the employee? Or the employee's spouse? Or can it be simply tax-free?

And on the company side... I assume if it's treated as revenue for the employee, then it's just operation expenses. But if it's tax-free, then it is it treated the same way as if it was regular travel expenses?

Thanks.

(British Columbia, Canada)