Depends on what you mean by talent. Innate physical ability? Bolt is one of the most athletically gifted humans ever, much moreso than even JBJ who is one of the most gifted MMA fighters ever. This is, however, specific to their sport. Bolt's body isn't as suited to fighting as JBJ's is, but it's the absolute ideal for sprinting, just as JBJ's is for fighting.
In terms of skill, obviously JBJ is in a completely different realm from Bolt. Sprinting takes next to no skill. Yes, there's certainly technique involved, but anyone can learn to be a sprinter with enough training, their only real limitation will be what their body can provide. Fighting is a totally different animal, there are so many factors both tangible and intangible that comparing them is just impossible. One is a skill sport (MMA), the other is a pure work sport (sprinting).
The last factor is, I guess, work ethic. Given that racing events are pretty much 100% based on how much work you put in combined with the body you're born with, it's easy to assume that Bolt has a better work ethic than JBJ. That combined with the fact that we know JBJ has been subject to bouts of laziness and atrophy means that Bolt almost certainly has a better work ethic. However, that isn't really talent as it's popularly defined.
Overall, JBJ is more "talented" in terms of the intangibles that make a fighter what they are. Bolt is a product of having the absolute perfect body for the sport he's in combined with the work ethic to maximize what he was born with. A lot of it comes down to how you define "talent" in regard to sports.
Also, they both use PEDs. You're kidding yourself if you don't think every Olympic athlete (in a sport where they provide a substantial benefit) aren't, they just have incredibly sophisticated and thorough programs that ensure that they'll never get caught. These athletes have the resources of entire countries behind them, beating WADA tests is trivial for them.
