The illustration shows the Pickle Fork attached to the Wing Spar.
Yes, it does, and generally, and in the case of Boeing jets, the wing box is enclosed by wing spars at the forward and rear faces of the wing box. So, the "pickle forks" are attached to the spars
and to the wing box, as considered as a larger assembly including the spars.
Wing bending could have a small effect on the wing box to fuselage connection, in transmitting bending loads from the wing box into the fuselage. I expect that the pickle forks would also be subjected to asymmetric loads associated with yaw, where the vertical stabilizer and wing (including possible differential power) act in opposition to twist the fuselage to wing connection. I'm aware of other types where the loads applied into the airframe from the vertical stabilizer and rudder are of concern.