No, unfortunately 018 numbers are not free to call on Vodafone mobile nor landline tariffs.
Cost of calling 018 numbers on Vodafone
018 numbers are a set of area code numbers which correspond to specific localities spread throughout the United Kingdom. In terms of call costs these are identical to other 01 and 02 numbers, which means normally you will have to pay an access charge to phone these numbers along with a per-minute rate. However if you have any inclusive minutes remaining on your pay as you go balance, monthly contract allowance or landline tariff you can use these instead of paying any monetary charge.
Beware of 118 numbers
118 numbers look similar to 018 numbers however these are much more expensive to call. They can have per-minute charges of up to several pounds per-minute as opposed to a maximum of 60p on Vodafone pay monthly mobile contracts. Furthermore you cannot use free minutes to call 118 premiums numbers unlike the 018 numbers and similar local helplines.