AFAIK, WF Visa Signature cards are only available by invitation only, unless something changed recently with their PC policy.
+1 yes exactly. From what one of the underwriters told me is that the siggy is primarily reserved for those with an extensive relationship with WF (PMA account, mortgage, auto loan, etc). My partner has a siggy, but he also holds the mortgage and his retirement there as well. We only share a joint checking account, so my relationship doesn't qualify. Although, there has to be some pretty decent internal scoring seeing as I got such a high limit with sub 650 ficos.