One thing that hasn't been mentioned is the exact siting of the light. For electrical purposes, bathrooms are divided into Zones.
Over the bath is Zone 1, and the light must be suitable for this location.
Otherwise, in general, regular fittings are OK.
As far as I know, 17th Edition Regs are not retrospective for new rentals. If they were, the whole bathroom would be protected by an RCD (earth trip), which would be even better.