It depends. And this applies to a bunch of characteristics, not just bond strength. Let me back up a step.
"Epoxy" is a collection of chemistries. There are a number of different base resins, a number of different kinds of hardeners, and various other things that can accelerate the reaction. Turning the liquid into a hard plastic entails a chemical reaction between the resin and hardener (the hardener isn't a catalyst that produces a fixed result based on the resin). The specific chemistry of the chosen resin and hardener combination produces results with different characteristics.
The setting time varies, and the end result can vary in all kinds of ways: performance differences, hardness, color, thermal and chemical properties, etc. For a particular purpose, the chemistry is optimized for the characteristics that are important (curing speed is just one; it's a balancing of requirements).
The difference between a fast-setting and slow-setting epoxy might involve different hardeners that produce different end products (for a slow- and fast-setting version of a particular product, the results should be pretty similar, since the products are designed for the same general purpose, and could be similar enough that you wouldn't notice a difference for your application). Or, it might accomplish faster setting by adding accelerators to the hardener, which would produce essentially the same end product.
With some products, you can even mix slow and fast hardeners to make a medium-speed epoxy. With other products, the slow and fast hardeners aren't compatible chemistries, and you can't.
It's not the curing time, itself, that can affect performance. But the chemistry that the product uses to accomplish the different setting speeds might affect performance. The only practical way to know is to contact the product manufacturer and ask (or test both versions).
If you have some chemistry background, you might find this paper by a scientist at one of the epoxy manufacturers relevant (it's a PDF link).