Yes, they are. Fully interchangeable.
As far as I know, TFtestkits sources their reagents from Taylor and repackages them in bottles with sizes that match the needs of residential pool owners.
Rather than selling kits with either 2oz bottles only or .75oz bottleyd only like Taylor, TFtestkits uses larger bottles for reagents you need more of, and smaller bottles for those you need less of. That's how they make their kits more cost effective.