I would check on the status of your iMessage on your iPhone first. If it went as a text message, it could mean there is a problem with your connection to iMessage, or it could be the other person's connection to iMessage. They may have also gotten another phone that is an Android device, are in a spot where there is no coverage, etc. There are a number of reasons that your message could go as a text. But you would see this if it attempted to send as an iMessage and if it failed and you had Send as SMS turned on, it will finally send as a text. You also would not see any difference in things if the contact blocked you. There is no outward notification on your end that would indicate you have been blocked, except the fact you don't get a reply after a while.
As far as the Mac, I'm not sure as I've never experienced a Send as SMS happen since I got my Mac and I can't say if it just displays Delivered if that was to happen when I used my iPhone. Again, on the Mac you will not see any outward notification that you have been blocked. As far as you would see is Delivered when you send a message to someone that has blocked you.