Bonding should be by the widest practical means. Wide cable tray is effective when it is made of zinc plated steel and carefully bonded at the ends to control panel and motor frame. Zinc plated sheet steel channel is also effective. The fact that the width is folded into a U shape does not matter. A closing lid helps. Solid steel conduit bonded at both ends is effective. The spiral construction of flexible conduit makes it less attractive for RF shielding because the spiral shape forms an inductor, even with partially shorted turns.
In addition, note that the common lead in this type of motor is usually white or purple. If there are additional leads in the run widing group, continue to use the ohmmeter to test the now-identified common and additional leads. Descending resistance will give you ascending speeds.