It may well turn out that trying to travel that way will be akin to going from New York to Beijing by tunnelling through the planet.
I don't think so, take into account solar flares cause fuxuations in the Earth magnetic field which might prevent the creation of a 'on planet' stable wormhole for any amount of time.
But I do see the possiblity of this research leading to a gate system that is at one quarter of the speed of light (in a vacuum) like what is shown in the anime Cowboy Bebop and maybe someday a warp drive.