osm wiki says next for lit=yes tag:

There are lights installed: the times of operation are assumed to be during the night, usually from evening civil twilight on Wikipedia to morning civil twilight. Lights do not need to be purpose-built to lit this specific object, for example footway lit by a billboard or nearby motorway still can be lit=yes.

so, if some light is available on the bus stop itself - then you can answer "yes". use common sense to decide how much light is acceptable to be "yes"