Minimum permissable load for a relay
Once the relay is on, it doesn't really matter what the input voltage is since the switched contacts don't see that voltage anyways. However, in some cases once the contacts are wetted, the minimum permissible load requirement may be relaxed. For this reason, people sometimes use a capacitor at the output of the relay to demand a large transient current as the switch closes, meeting the requirement for contact wetting momentarily and then backing off. For a given capacitor, the profile of the current as the switch closes will depend on input voltage. Unfortunately, it seems your datasheet doesn't provide a lot of information about the wetting characteristics. I would conservatively take the information given to mean 100mA is always required, even once the switch is closed (and therefore regardless of the voltage). If you want to experiment and determine the wetting characteristics, however, you may be able to dodge the spec...