It really depends if it's 'worth it' for you. 😀 You haven't mentioned anything about your build, so I'll assume that you have a Slot 1/i440BX PC or similar.
If you're only doing it for performance reasons, then I would say that no, it's not worth it (2 x Voodoo 2s in SLI have about the same performance as a Voodoo 3 2000).
The issue is that there are no Glide-only games (that I can think of) which would benefit from an additional Voodoo 2 card. So you'd be much better off with a faster nVIDIA card + your current Voodoo 2. This way you would get the best of both worlds: much better performance and visual quality for newer games + compatibility with older titles.
Even a GeForce 2 MX 400 (which is ultra-cheap) would be a much better choice performance-wise. Or, even better, a card like the GeForce 4 MX 440/460 that is still pretty cheap but MUCH faster.
But, then again, performance isn't everything, and having a Voodoo 2 SLI build is just... cool. 😀 Especially if it's not your only retro PC (and if you can afford it), I would say that... yes, it would be worth it. 😁
The cards don't have to match (although it would be nice if they did). You can use the FastVoodoo drivers with non-matching cards and they will work well.
Banshee is not a good alternative, that one is a slow card (for games where that matters - i.e. games that take advantage of multitexturing).
2 x PGA132 / 5 x Socket 3 / 9 x Socket 7 / 8 x SS7 / 12 x Socket 8 / 11 x Slot 1 / 3 x Slot A
5 x Socket 370 / 8 x Socket A / 2 x Socket 478 / 2 x Socket 754 / 3 x Socket 939 / 4 x LGA775 / 1 x LGA1155
Current rig: Ryzen 5 3600X
Backup rig: Core i7 7700k