Generic Classes have the possibility to gain different class features in exchange of a bonus feat:
For the purposes of these classes, the following class features can be selected in place of bonus feats (unless noted, each may only be selected once).
The Sneak Attack class features that can be selected are:
Sneak Attack (Ex)
As the rogue ability, but +2d6 on damage rolls. Prerequisites: Hide 4 ranks, Move Silently 4 ranks.
Improved Sneak Attack (Ex)
Add +3d6 to your sneak attack damage. Prerequisites: Hide 11 ranks, Move Silently 11 ranks, sneak attack.
Greater Sneak Attack (Ex)
Add +4d6 to your sneak attack damage. Prerequisites: Hide 18 ranks, Move Silently 18 ranks, sneak attack, improved sneak attack.
Do these three class features stack together?