How hard is it to move cities?

Hello all, am in a bit of a sticky situation. Have been together with my GF for a few years now (she is a year older). We both were originally intending on staying together in the Bay Area long term. She was starting out in NYC. However, she recently let me know that she would like to stay in NYC area for the foreseeable future instead of the bay area. She has family who live in the surrounding metros (LI, Westchester) and likes their lifestyle more than SF and would like to stay there. However, my FT job is in SF (just graduated college). My firm does not allow mobility for the first few months or so as expected. How hard is it to get a lateral move between cities for a BB firm? 

For reference, she is in a much more demanding/more lucrative job than me and would prefer to stay there whereas being in finance, I feel I will have more opportunities in NYC.