Python - 77 Chars
n=input()
for k in range(6*n):print' '*k+('*'*12+' '*(k%6*2+1))[-12:]*(n-k/6)
n=input()
for k in range(6*n):j=1+k%6*2;print' '*k+('*'*(12-j)+' '*j)*(n-k/6)
89 Chars for the bonus
n=input();R=range(6*n)
for k in R+R[::-1]:print' '*k+('*'*11+' '*11)[k%6*2:][:12]*(n-k/6)
114 Chars Version just using string replacements
u,v=' *';s=(v*11+u)*input()
while s.strip():print s;s=u+s.replace(*((v*2+u,u*3),(v*1+u*10,v*11))[' * 'in s])[:-2]
Unk Chars all in one statement, should work w/ 2.x and 3.x. The enumerate() is to allow the single input() to work for both places you need to use it.
print ('\n'.join('\n'.join(((' '*(6*n))+' '.join(('%s%s%s'%(' '*(5-x),'*'*(2*x+1),' '*(5-x)) for m in range(i + 1)))) for x in range(5,-1,-1)) for n, i in enumerate(range(int(input())-1,-1,-1))))
Yet Another Method
def f(n): print '\n'.join(' '*6*(n-r)+(' '*(5-l)+'*'*(l*2+1)+' '*(5-l)+' ')*r for r in xrange(1, n+1) for l in xrange(6))
f(input())
