Going for a tether trump to immediate ledge get-up should be one of the main focuses of this AT imo. I have a whole heap written about it in the AT thread toward the end which I highly recommend for everyone to read in full, but essentially doing the ledge get-up will still trump the opponent if they don't do a buffered ledge option, and the only ledge options they can buffer are roll, attack, or jump, which leaves you, having just done a normal get-up, in a prime position to punish these options.
As for Z-dropping the bomb as part of the tether trump, well that's potentially even better when the opponent is at high percents when you think about it. See, one of the main issues with doing the version of the tether trump that involves the immediate ledge get-up is that it doesn't give you a guaranteed punish for when the opponent actually gets trumped. It puts the opponent in a bad position of having to recover on-stage or else suffer a ledge-grab without invulnerability frames, but for some characters this isn't the end of the world. If you do a z-dropped bomb as part of your tether trump however, as you said, they will just get hit by the bomb immediately after being trumped, and if they are at high percents this should give us enough time to combo out of that. This more applies to Link though when I think about it, because of the greater knockback/hitstun on his bombs, but still.