Example: http://i.imgur.com/DKC1WTJ.png
BOP cfg: http://i.imgur.com/ZHztmTC.png
Forge CFG: http://i.imgur.com/8XXGVJE.png

Not a bug, we just haven't added support yet.

EDIT: Nevermind about what I said after this, didn't realise you intentionally turned off our new textures (although you must be crazy to think Forge's one looks better :P )

I had the custom ones on, but I turned them off and didn't see a difference

The difference is pretty noticable really, our version has fixed shading that looks much closer to Vanilla buckets, unlike Forge's which are a bit of a disaster in that regard... Anyways, that's a rant for another day :)

Here's an image for reference:

Yeah, I have forge's model off and BoP's on right now and it is vanilla. Custom model doesn't seem to be working for me

Just tested it with only forge and BoP, vanilla bucket. (forge bucket disabled and BoP's enabled)

Yeah, it's still a valid issue, although that should make it far less noticable

Does that mean that resourcepack makers have to replace their bucket in the BoP assets for it to work or will the forge assets suffice?

Resource pack makers should be able to replace it as normal (i.e. Forge's assets)

In my case it's the other way around. I installed Forge in version 1.11 and the minecraft bucket vanilla is in the vanilla version, and the buckets of the mod Biomes' Plenty are in the version you just discussed, the bucket the forge adds (texture).
What do I do to leave the bucket of vanilla with the texture of what comes in the forge?