Most of the pumpkin flavor comes from the spices, I see you used .5 tsp of cinnamon and pumpkin pie spice. From the recipes I have seen about 1 to 3 tsp of each spice are used, depending on the spice. If you can't taste any of it, you could try steeping some pumpkin pie spice, maybe 1 or 1 1/2 tsp in about a cup of water for about 10 minutes and then add to a secondary.
I added about 5 tsps total of cinnamon, nutmeg, and clove to my pumpkin ale during the boil, took a sample the other day and could really taste it. So you could give the steeping option a try.
I'm going to bottle condition my pumpkin ale (8% alcohol) for about 5 weeks, though the only reason I'm doing that is so my buddies and I can crack them open on Halloween.