src1.GetBounds().center returns the local space center of the object.
Lets say the 2 objects have the pivot in the center -
j = src.transform.position => center of sprite #1
k = src.transform.position + Vector3(src.GetBounds().extents.x, 0, 0) => right edge of sprite #1
l = k + Vector3(second.GetBounds().extents.x, 0, 0) => positions second sprite at the right of sprite #1
To offset this correctly for any arbitrary anchor position for sprite #1 and #2, use this:
b.transform.position = a.transform.position + new Vector3(a.GetBounds().extents.x + a.GetBounds().center.x + b.GetBounds().extents.x - b.GetBounds().center.x, 0, 0);
This positions sprite b tiled to the right of sprite a.