Can I use Apple TV to stream HBOGO thru my HD TV

Yes.

BTW you would be better off asking questions about the Apple TV in the Apple TV community.

I added Apple TV to the list of devices and thought I had succeeded in posting the question in the Apple TV community.

No in order to post to a specific community you need to select it when you create your post (if you are not in the right community when you create your post)

These are at the bottom of the window where you create your post.

Well done. See my reply to the OP. - ÇÇÇ

worry not... it happens a lot - I will ask our Hosts to move this to Apple TV forum forthwith. GeoCo explained it all perfectly. - ÇÇÇ