They may be refering to Jacquard's acid dyes, but Jacquard has several fabric dyes. If you are dyeing wool, you want the acid dye. The best price I have found is here:
Jacquard acid dye
Any dye that says it is for natural fibers should work on wool. Cotton and wool need different dyes, so if a dye says it is for all natural fibers, it probably has two dyes in it, one for wool and one for cotton, etc. I think that for wool it is best to get a regular acid dye.