Yes! 0808 numbers are completely free to call from a UK phone, be it with EE or any other network. 0808 numbers have been freephone numbers for many years for landline callers, and since June 2015 have been free to call from all UK mobile phones too.
0808 and 0800 are the two main freephone number ranges in the UK. Any UK numbers prefixed with 0800 or 0808 are free to call from landlines and mobiles including those on the EE network.