Like dr dude said in his answer a Pokémon with it's Hidden Ability should still have the Hidden Ability of the Pokémon it evolves into.
Are you 100% sure your Eevee had Anticipation as it's Ability and not Adaptability or Run Away?
Anticipation is Eevee's Hidden Ability while Adaptability and Run Away are it's Normal Abilities. A lot of players often get Anticipation and Adaptability mixed up as to which is Eevee's Hidden Ability.
If your Eevee had Anticapation as it's Ability when evolved into a Vaporeon through the use of a Water Stone it would have it's Hidden Ability Hydration, while if Eevee had Adaptability or Run Away when it evolved into a Vaporeon it would have Water Absorb as it's Ability.
Source: Eevee, Vaporeon, Abilities
Hope I helped :)