Here's the flyby in the geocentric mean ecliptic and equinox of J2000 reference frame.
The graph covers 90 days before and after the spacecraft perigee epoch.
The following objects are shown: Earth (single blue dot), OSIRIS-REx, Sun (in the geocentric frame, the Sun orbits the Earth), Bennu, Moon (its orbit is very small in this scale).
Notice how the flyby changed the spacecraft orbital plane to match Bennu orbital inclination.
The graph shows the distance between the spacecraft and the Earth (blue plot) and the spacecraft osculating orbital inclination to the ecliptic plane of J2000 (orange plot).
The green vertical lines represent the Earth sphere of influence (the distance from the Earth where the gravitational acceleration of the Earth and of the Sun are the same).
The spacecraft orbital inclination increased from about 0.15 deg before the SOI to about 6.5 deg after the SOI.