Multiple ETA Applications
In most cases, the person applying for an ETA will apply for more than 1 ETA Visa. (partner, kids, friends etc)
Each person entering Australia MUST have a visa.
Please note that whilst it is annoying, you are required by law to enter the details of 1 person at a time and process these details individually.
You can apply for many ETA Visas 1 after the other, however, they can only be applied for 1 at a time.