In general
The amount of the credit allowed under subsection (a) shall be increased by so much of the sum of—
(A) so much of the employer’s collectively bargained defined benefit pension plan contributions as are properly allocable to the qualified family leave wages for which such credit is so allowed, plus
(B) so much of the employer’s collectively bargained apprenticeship program contributions as are properly allocable to the qualified family leave wages for which such credit is so allowed.