Bus lanes were put in place, at some expense to the public, to provide on-street priority for bus-based public transport. Their goal is to make bus services more reliable and efficient and to attract more people to switch from private cars to public transport.
Emergency services may also use the lanes, and taxis and bicycles are permitted to use with-flow lanes. The decision in the early days of bus lanes to allow taxis to use with-flow bus lanes was based on the fact that they are available for on-street hire.
Since the creation of the bus lane network, there have been many requests to extend bus lanes to various other categories of traffic. My predecessors and I have always rejected these requests, as allowing further categories of traffic into the lanes would reduce their efficiency for their core purpose. While the specific issue of taxis being allowed to use contra-flow lanes has not been mentioned, to my knowledge, in recent years, there is no plan to extend the use of bus lanes in any respect.
The provision of taxi ranks in Dublin city is a matter for Dublin City Council, and neither I nor my Department has any role in it.