Rather than defining it in wp-config.php, a php.ini file can allow you to set not only the memory, but also max_execution_time, file upload size, and other settings that frequently cause issues with WordPress themes. Make sure you kill the PHP processes (some cPanel dashboards offer it) for it to go into effect. Or you can toggle the PHP version to do the same effect.
Alternatively, you can also usually modify the limits in the PHP settings inside of cPanel, if that's what you're using (and that is what BlueHost uses) and just change the limits of what I mentioned above there without manually setting them in a php.ini file.
You can verify your settings have gone into effect by creating a phpinfo.php file with <? phpinfo(); ?>
and then call that file from your browser to verify the new limits are in effect, as that will show all the PHP values for your hosting environment / account.