Not all booking classes are for all routes. V/W are only for US to non-Korea routes, so do not exist on US-Korea route. G is usually for group tour only. Some of them are not allowed to be attached to US domestic sector (although travel agencies do this secretly for us.) SFO-ICN usually has more classes purchase-able due to higher competition. So depending on your origin and destination, one-way or round trip, duration of your travel, and season, you'll have different sets of available classes, but not from your elite status at all. TA may be helpful, but still you'll have very limited choices in terms of booking class.