You don't have any tag skills with gifted. It might seem like you do on the character creation sheet, but that's only an unfortunate remainder of the screen being a bit more hardcoded than desired. We might find some solution to it later, but that's not a priority right now. You can't make a gifted char with tag skills.
The way skill points work after lvl 24 is the same with or without the gifted trait. For primary weapon skills, that is to say, Small guns, Big Guns, Energy Weapons or Hth Combat, your highest skill becomes the cap after level 24. You can raise the other primary weapon skills only to that level. For example, let's say at lvl 24 you have the following weapon skills:
Small Guns: 225
Big Guns: 90
Energy Weapons: 60
Hth Combat: 170
Now in this example, your maximum primary weapon skill is the small guns skill, which is at 225. That means you can only raise Big Guns, Energy Weapons and Hth Combat to that level, not above it. Your Small guns can't be raised at all after lvl 24, in this example.
For secondary skills, ie Throwing, Traps, First Aid, Doctor, Leadership and Sneak, the second highest of your skills becomes the cap for the rest. Example: Your secondary skills at level 24 are like this:
Throwing: 60
Traps: 60
First Aid: 175
Doctor: 60
Sneak: 150
Leadership: 125
Now your second highest secondary skill (I know, that's a mouthful) is the Sneak skill, which is at 150. That means that after level 24, you can only increase Throwing, Traps, Doctor and Leadership, and only up to 150, not beyond.
Or to put it simply, with the gifted trait, post lvl-24 skill points work just as if your highest skills were your tagged skills.