Yes, one of the function of attunement card is to increase your energy capacity. From my experience spamming it for 4-5 days before moving on to spam mostly energy expansion I would say that it helps to increase energy threshold slightly, not as much as energy expansion but it helps in this area.
On the other hand, energy expansion is mostly about expanding energy so you can handle more fields/wearable like mandala tag nft etc. From the description it helps making you more sensible to energy as well but sources on this forum suggested that attunement card (don’t forget to boost it once) is good at making you more sensible to fields, which I think means that you will get better result from listening to fields similar to using SLR/PONR/vibration/others. So I spam both, when I have time I spam energy expansion, and if I know that I won’t be able to use the card after about 20minutes I will do attunement and wait an hour to see which one to use next. Or I just use attunement if I feel lazy or want to be more relax say on Sunday.