Yes, the Bonobus is cheaper, the farther you travel, the cheaper it is. Check out http://www.titsa.com - the Tenerife Bus company. You can buy 12 and 30 euro Bonobus passes/cards from lots of places. You put them in a machine on the bus and tell the driver where you want to go. He then works it out and the amount is deducted from your card (which is card and about the size of a credit card) The card shows the amount you have spent, and also what the remaining balance is. They are easy to use - we regularly use the buses when in Tenerife.

Hope that is of some use (and makes sense)

Thanks very much for the reply.

Made a small mistake in my question, "put it into a machine and press a buttom" should be button and not buttom

It can be difficult to find the shop etc which sells the cards.

Bus drivers do not sell them. Only certain shops and the larger terminal,

Very good value,

Billyboy.