Bone effecting part of mesh it has 0 influence on? though its my second time modeling, its my first time weight painting + working with mesh aspects particularly close to one another. 



seen above the right arm bone has absolutely no influence to the belt-tail part of the mesh


however when the arm is moved in the pose menu it moves with it! any thoughts on how to fix this?
yes, on the object property panel (to your right) go to the tab where it shows a icon,triangle of vertices. Look for the Vertex group panel there.
You´ll see a list of "weight groups" you need to locate the one that is named exactly like the bone is afecting your tail. Once you find it, you´ll see your arm turns on with color (in your image is red) and then go to the T panel on your viewport (press T) and on the tool select SUBSTRACT brush. Place the settings to : 1 in weight. 1 in strenght. Now, paint the TAIL. 

This will substract instantly every weight influence the tail is having from any other bone.

Once you´re done, switch back to DRAW in your tool palette.

Thank you for your consideration to vote me as the answer by clicking to the left :the icon with a check mark and upvote this answer.

BFCT_Schiller