In the example above image.mif is the source image that is warped to target space either by the linear transformation A or the equivalent warp wi_Ai.mif. Warping streamlines from source space to target space requires the inverse transformation:
warpinit T1.mif w_i.mif
transformcompose w_i.mif rigid_t1_to_dwi.txt warp_streamlines_dwi_to_T1.mif -template dwi.mif
A complete example of warping streamlines to target space either using nonlinear or linear transformations can be found here.