What you're talking about is not an "afterparty," it's a reception. It's a specific part of a wedding, and as others have mentioned, it's perfectly fine in North American etiquette to invite people to the reception but not the ceremony.
However, I agree with the others that having a destination reception for people not invited to the destination wedding isn't a good plan. Ask yourself if you'd give up a weekend because a friend who lives near you invited you to a luncheon three hours away. If they were a really good friend, you'd probably go but grumble about the inconvenience of it. If they weren't very close, you'd probably not go.
Have your reception nearer your home. You'll have more guests willing to attend, and it shows more consideration for them.