First of all, as ddeimeke said, aliases by default are not expanded in non-interactive shells.
Second, .bashrc is not read by non-interactive shells unless you set the BASH_ENV environment variable.
But most importantly: don't do that! Please? One day you will move that script somewhere where the necessary aliases are not set and it will break again.
Instead set and use environment variables as shortcuts in your script:
#!/bin/bash
CMDA=/path/to/gizmo
CMDB=/path/to/huzzah.sh
for file in "$@"
do
$CMDA "$file"
$CMDB "$file"
done