Facebook is tricky it works on number of comments. If you or someone else comments on your post (reply doesn't count) more friends will see it. In general it works that first people to see your posts are those who you interacted with recently for example through private message or comments on their walls. If you get 3 comments in your post, 30% of your friends will see it, 5 comments = 50%, 10 comments = 100% of your friends will see it in their feed.
Hope this helps @mattclarke
Yes that´s right @dashfit, thanks for your additional information. And if a friend will like your post, more of your friends and friends of your friends will see the post @mattclarke.
All true, but the people I tag in a post should always see it, right?
yes, they should receive a notification about the tag. Unless they have disabled notifications I don't see a reason why would they not receive it.
Yes, they should see it in the globe at the top right corner.