[The following assumes that your unspecified "logging issue" was related to missing environment setup, normally inherited from your profile.]
The `-l` option tells bash to read all the various "profile" scripts, from `/etc` and from your home directory. Bash normally only does this for interactive sessions (in which bash is run without any command line parameters).
Normal scripts have no business reading the profile; they're supposed to run in the environment they were given. That said, you might want to do this for personal scripts, maybe, if they're tightly bound to your environment and you plan to run them outside of a normal session.
A crontab is one example of running a script outside your session, so yes, go do it!
If the script is purely for the use of the crontab then adding `-l` to the shebang is fine. If you might use the script other ways then consider fixing the environment problem in the crontab itself:
0 * * * * bash -l hourly.sh