You can use GOCALLIDD anywhere in the Philippines. However, the promo will be deactivated while you're abroad and the original expiration date will apply.
For example, you registered to GOCALLIDD 199 on January 1 and you will be leaving the country from January 2 to 5. While abroad, you will be charged with regular roaming rates for your calls abroad. Upon returning the Philippines, you can enjoy GOCALLIDD 199 again. Despite the deactivation from January 2 to 5, your GOCALLIDD 199 will still expire on January 30.