How to add a tag from one Mod to an item in another mod in a third mod

Hi,

There was a simiilar question asked of adding a tag from one mod and adding it to an item in your mod. That I understood from 

https://mcreator.net/forum/82751/ultimate-integration-guide-how-use-other-mods-resources-workspace-workarounds

Here's the example I have currently have however:

Biomes o Plenty, Biome Makeover, and Swampy_Swamps all have Cattails, but only Biome Makeover has a recipe for Thatched block. What I've done so far is copy the recipe and replaced the Biome Makeover with Swampy_swamp. But then I saw that the Cattails has been tagged "Reed" in the recipe.

Is there a way to add the Biome Makeover "Reed" tag onto the Swampy_Swamps Cattail in my Mod?  It would save having to keep duplicating the recipe.

I haven't coded in a decade, so I'm trying to get back in with learning Minecraft modding. I might have missed something in the guide.

Thanks in advanced