Syntastic works great in my system with hdevtools and hlint. But if I'm editing a file under a test directory, importing packages that are exclusively under the test-suite configuration of the cabal package, it marks my imports as bogus and tells me to include them in my cabal file. The same problem happens with the hs-source-dir, it only finds the ones under the library or executable directory.
There is no silver bullet. You can either set g:syntastic_haskell_hdevtools_args and friends to the proper flags for your project, or write a wrapper script similar to this and point g:syntastic_haskell_hdevtools_exec to it. Syntastic has no built-in support for looking at cabal files.