Wow, 2 years into marriage and she can't get a b'day present right?
Early days yet, you'll get to an (inevitable) point where nothing is a surprise, nothing is novel, and even that your relationship means you don't particularly bother with none-essentials like presents.
T'was my 40th last year, got a medium sized camelbak, still "on a promise" for my proper present, doesn't bother me what/when, it'll arrive at the right time.
If you can't see you chair making workshop adding anything to your life, then go on it, use the weekend as an excuse for a prolonged piss up, or, use the skill, sell some of the product, spend hard earned on the bike stuff you require.