Guild Wars 2

i was just wondering if the gem rewards were only for gems bought with real money or if these purchases also include gems traded for gold in game?

In the past, freebies for spending gems only applied to those gems bought with cash. I suspect the same with this promotion.

and i figured that was the case, but they might want to specify that somewhere

They do say “Purchased” don’t they? That implies real money. You “exchange” gold for gems.

Is there some way I can see how many gems I have purchased on my account in December?

Try checking the email associated with your account. I believe they send you a receipt for every purchase/registered code.

Or check your bank statements or credit card and so on.