Are you sure $userinfo.membership is passed on to the page interpreting the TPL in every situation? because if not, it will always use the ELSE.
You could check it by making it something like:
Code:
<strong>Membership:</strong> {if $userinfo.membership eq 'Wholesale'}Wholesale
{elseif $userinfo.membership eq 'Retail'}Retail
{else}
NO MEMBERSHIP
{/if}
It will give you a bit of insight into what's going on.
You could also echo the $userinfo.membership to see what's in the variable itself.