Diglett LV 24 - Scratch, bide, dig, growl
I'm assuming you're using him for dig right now and getting him up to a Dugtrio. That's all fine and dandy, but you got your ground type covered by Golem.
Zapdos LV 53 - Thunder, thundershock, fly, drill peck
Pretty solid as far as Zapdos goes, given his high stats.
Gengar LV 40 - Dream eater, confuse ray, night shade, hypnosis
Again, pretty solid. Consider dropping Confuse Ray for a direct damage attack.
Alakazam LV 41 - Teleport, recover, psychic, psybeam
Perfect, except for Teleport. It's a waste of a very powerful attack slot.
Golem LV 40 - Selfdestruct, earthquake, rock throw, mega punch
Blastoise LV 41 - Surf, bubblebeam, ice beam, strength
Not much you can do about it now, but teaching HM moves to your end team pokemon is usually a terrible idea, because you can't overwrite them later on. Surf is good, but strength is not so. Drop Bubblebeam for Hydropump when you get the chance.
Fatal flaw in most teams is a heavy reliance on elemental type pokemon, because it's assumed that they're the only ones who get the chance to learn the elemental type moves. Through TMs, Tauros becomes essentially the most powerful pokemon, because he has no weaknesses and can be taught Thunder, Fire Blast, Blizzard, and pretty much any other final tier move.