Is this a good Raichu moveset Volt Tackle Surf Grass Knot Wish

No, it's not a good moveset.

By the way, I see you have one of those Pikachus given away in New York, am I right?

Volt tackle is a physical attack, while surf and grass knot are special attacks. It's better to concentrate on just physical attacks, or just special attacks, but not both.

Delete volt tackle for thunderbolt. Volt tackle has a 33% recoil rate (similar to double-edge), so it will do a lot of damage to the user.

Raichu is too frail to pull off Wish. If Raichu wishes one turn, it will most likely be knocked out the very next turn.

Surf and grass knot are both good options, as they take care of ground type Pokemon. However, I think having both is redundant. Just keep one of them. Personally I'd go with surf, because grass knot does variable damage and won't hit small opponents as hard. However, that's up to you.

As for your other options, Focus Blast is good, although not very accurate. Nasty Plot is a good idea too, but since you're using an event Pikachu, you can't add that (nasty plot is an egg move). Hidden Power is a good idea if your Pokemon has good IVs and the type is good.

Thunderbolt
Surf/Grass Knot
Focus Blast
Hidden Power

or maybe

Thunderbolt
Surf
Grass Knot
Focus Blast

If you're using it for competitive battling, I suggest going with a modest (+Sp. Atk/-Atk) or a timid (+Spd/-Atk) nature. Focus sash is a good item to equip it.
dude! foget these people!!!i think those are awsome attacks!(;