Cedar tree material bonus

The bonus for Mentem and Herbam only counts if these arts are requisites, correct?

I searched the forum for the same thing and only found another incredulous post

Considering that the only way to have spells with Mentem AND Herbam requisite would be to build them purposefully with that bonus in mind, I think that the only reasonable interpretation is "Mentem OR Herbam requisite".

Or maybe 2 separate bonuses: +5 for spells with a Mentem requisite, +5 for spells with a Herbam requisite
(takes an extra season to get the effect from a Talisman)

For it to be useful at all, I interpret it as "with Mentem OR Herbam requisites".
But yes, requisites - not as primary Arts. For some reason - I'd have preferred it more useful as primary Arts, but I'll have top rely on the author writing this deliberately.