You can definitely apply for another line even without a credit card. There might be a need to submit additional documents like proof of financial capacity. But this, of course, will depend on your credit limit. You may visit this link Postpaid | Help and Support for the complete list of Postpaid plan requirements.
To apply for another line, I suggest you to contact (02)730-1010, visit the nearest Globe Store, or visit Globe Online Shop.
Hope this helps.
thank you Paulo` :-)