I myself am a Sikh, but I do not know what Sikhism as a whole reacts to Wicca...I find a kinship that they too are persecuted for their beliefs.......any Sikh knows that religious persecution is uncalled for....
Wicca can be VERY lo sly compared to Hinduism as they both may be thought of a pantheistic religions. The 9Th Sikh guru sacrificed his life for the Kashmir pundits(Hindus) thus as Sikhs we should follow his example and basically stick up for them and ourselves! these nothing wrong at all with a Sikh being friends with vicunas/hindus etc... so basically as with all religions we see Wicca as an alternate path to god and Misha.