I've been looking through the vanilla code, but I'm not finding how you get the respawn location.  Or if it's easier, how would you use the vanilla respawn system to place the player upon re-entering the overworld from a custom dimension? (doing this inside my dimension's Teleporter class)  I couldn't find where this is done on exiting the credits screen in the vanilla code.

ChunkCoordinates cc = player.getBedLocation(player.dimension);
if (cc != null) {
cc = EntityPlayer.verifyRespawnCoordinates(player.worldObj, cc, player.isSpawnForced(player.dimension));
}
if (cc == null) {
cc = player.worldObj.getSpawnPoint();
}

That is the meat of the code adapted from ServerConfigurationManager#respawnPlayer.

I had to remove the verify section, with it in it was spawning me ~1000 blocks from the bed, but after I did that, everything worked great.