Should, yes, but demonstrably don’t for some ST customers, including some who have zigbee mappings of their networks. It’s a really weird situation. Clearly the bulbs are identified as repeaters by the coordinator. But some people have some messages getting lost.
Hue Bridge
Lightbulbs connected to a hue bridge are repeaters–but only for other devices attached to the same bridge. They essentially form their own mini network. So they won’t help with nearby sensors.
Zwave bulbs
Zwave lightbulbs like those from Linear and aeotec typically are repeaters – – but only for Z wave. These can actually be very useful in some specific use cases like getting zwave signal down basement stairs or across a garage.
What brand and model of lightbulbs are you using?