By default modelines are only read in the top five lines or bottom five lines of the file. If you can rearrange your Makefile this would probably be the best solution.
If this is not an option you can change do add the following to your vimrc.
autocmd FileType make set modelines=0
To turn modelines off. If you change 0 to a different number, this will change the number of lines that are checked at the top and bottom of the files.
Lastly you can just change the target name since it seems to be arbitrary.