This is a question that is posed to our customer service quite frequently.
Unfortunately, there is no short yes or no answer.
For the most part, if you are matching up the pin-base and the wattage, bulbs should be interchangeable regardless of manufacturer.
It’s straightforward with bulbs like four pin, G24q-3 base. If you match that information up exactly, they should be interchangeable.
It’s much harder with 2 C circular bulbs because different manufacturers will align the pins slightly differently.
Some manufacturers don’t publish a “base type”, which makes matching bulbs nearly impossible. It’s very difficult, for example, to match up Lights of America to other brands successfully.
The future of lighting is the GU24 base, which is completely interchangeable regardless of manufacturer. A nice thing about this design is that if the fixture takes a 26w bulb, you can use any GU24 bulb with a wattage bulb equal to *or less than* 26w.