Well, Since I leveled up my hunter alt to lvl 80 with name Aedari I cant see the entrance to MOTHERLODE and at the same time when I do delves dont receive bounty bonus after complete them, it happens only with that toon.
Also possible you need to grab the quest to start it from Gallywix if horde or do the zuldazar foothold quest if on Alliance.
What do you mean by this? Delves are a character specific experience and you will only receive rewards on that character that ran the Delve. In order to receive the extra Bounty chest you needed to have used a Delvers Bounty map. It is a one use item for the character that used it.
You get one of the maps by beating the Underpin boss if he spawns in a delve. Occasionally can be found in Bountiful chests at the end of a delve run.