The gold postboxes were for members of Team GB. The statement "If it is being done across the water, we should do it here as well" is misleading because it
was done in NI as well. For example, paralympian Bethany Firth of Seaforde, NI got a gold postbox in her honour for winning 100m backstroke gold.
Team GB incorporates Northern Ireland, but not Ireland!
http://en.wikipedia.org/wiki/Team_GB
Team GB is the brand name used since 1999 by the British Olympic Association (BOA) and British Paralympic Association for their Great Britain and Northern Ireland Olympic team. The brand was developed after the 1996 Summer Olympics and is now a trademark of the BOA. It is meant to unify the team as one body, irrespective of each member athlete's particular sport. It forms part of a marketing strategy, where its brevity is seen as beneficial. The brand is seen as controversial by some for focussing on Great Britain, at the expense of Northern Ireland, with critics suggesting it be changed to Team UK, something the BOA has so far rejected.