When a post doesn't end up on your Blog automatically, you go to that post in your Post channel and hit the reblog button. This works in all HIVE based blogging user interfaces. Am actually not sure where people look when browsing. Post channel only posts as well as Post/Blog channel posts are shown in searches, tags, communities. Only when you go to someones profile, you'll usually get the Blog channel be default and need a mouse click extra to go to the Post channel.

But as said, to get a Post channel post into your Blog channel, just hit the reblog button.

Tip: In case you like to include your YT publication into your 3Speak one, this is possible. Just add this to the textual section when creating your 3Speak post.