You are forgetting to add the texting to the base calling minute plan of $70. If you add $30 for the texting you get the $100 you are seeing on your bill.
1400 minute plan for 2 lines = $89.98 = $70.00 + $9.99 + $9.99
If you add the unlimited texting to make it a Talk & Text plan it will be:
$119.98 = $70.00 + $9.99 + $9.99 + $30
Verizon takes the base minute charge with the texting charge and lumps it together in the Account Charges and Credits to be the $100.00 which you see on your bill.