"Secondary spell circles are any other circles the character knows that do not include the cast spell." -- https://gswiki.play.net/mediawiki/index.php/Casting_strength under 'Secondary Circle Bonus' header

Is this in fact accurate? ALL spells known--such as a Cleric casting a Minor Mental spell, or a Bard casting a Major Elemental spell--count as secondaries?

I'm about to start putting together some Rainbow Hoolahoop/502 rods for the Bard to use, want to make sure my CS math is accurate. :)