The total discount is still wrong. Here is the rule:
//eCart Rule
function WAEC_eCart_Weinrabatt10()  {
  $totalDiscount = 0;
  if (true && ((( $this->ConditionalTotal("Quantity", "PRODKATID", "7") - $this->ConditionalTotal("Quantity", "Primeur", "1") >= 96 )))) {
    $totalDiscount += ($this->ConditionalTotal("TotalPrice", "PRODKATID", "7") * 0.1);//Result
  }
  return WA_eCart_FormatNumber($totalDiscount, $this->ForceDecimalsC, $this->DecimalPlacesC);
}
//eCart Rule  
What happens is that if there are >= 96 bottles of non primeru wines in the cart, the total discount (10%) is counted on the non-primeur AND the primeur wines in the cart.
Furthermore I tried to extend the other discount(s) but received a parse error:
(Discount of 3% for 24 - 47 bottles of wines):
Current rule without primeur wines:
//eCart Rule
function WAEC_eCart_Weinrabatt3()  {
  $totalDiscount = 0;
  if (true && (($this->ConditionalTotal("Quantity", "PRODKATID", "7") >= 24) && ($this->ConditionalTotal("Quantity", "PRODKATID", "7") <= 47))) {
    $totalDiscount += ($this->ConditionalTotal("TotalPrice", "PRODKATID", "7") * 0.03);//Result
  }
  return WA_eCart_FormatNumber($totalDiscount, $this->ForceDecimalsC, $this->DecimalPlacesC);
}
//eCart Rule
New rule with primeur wines, causing parse error:
//eCart Rule
function WAEC_eCart_Weinrabatt3()  {
  $totalDiscount = 0;
  if (true && ((( $this->ConditionalTotal("Quantity", "PRODKATID", "7") - $this->ConditionalTotal("Quantity", "Primeur", "1") >= 24  )) && (( $this->ConditionalTotal("Quantity", "PRODKATID", "7") - $this->ConditionalTotal("Quantity", "Primeur", "1") <= 47  )))) {
    $totalDiscount += ($this->ConditionalTotal("TotalPrice", "PRODKATID", "7") * 0.03);//Result
  }
  return WA_eCart_FormatNumber($totalDiscount, $this->ForceDecimalsC, $this->DecimalPlacesC);
}
//eCart Rule
thanks for any additional help in advance :-)