bending moment diagram is the diagram that represents the moments of the beam at different locations of the beam,whereas......influence line diagram represents that by the variation of different loads on the beam at different locations how a particular reaction or moment,shear force etc varying in that beam.
Influence lines generally drawn for moving loads only.....
we can draw the influence line diagram for any particular aspect (moment,single support reaction),but bending moment diagram is different.
References:search in thandava moorthy textbook and
Michael J. Ryall, Gerard A. R. Parke, John E. Harding textbook as well.