I'd use them, but I might sprinkle some lime over the soil before applying. Although the mulch on top of the soil won't really affect the soil pH, alliums really prefer a basic soil pH rather than an acidic soil pH, so if adding a particularly acidic mulch I'd probably add a little lime. It would eventually be worked into the soil, etc., and everything will work its way back into balance. My mulch is almost all ground up leaves, and even for that I apply lime.

Good advice, pine needles are acidic the lime won't hurt, and will mature (which it does slowly) to be also available to second season crops once the garlic is harvested. I got caught short on time and energy this autumn or I would have prepared beds for next years tomatoes and peppers, and limed them. That fall lime seems to me to keep blossom end rot to a minimum. Mulch for garlic has to be the sort that does not pack down over winter, since the new shoots have to come up through it.

I don't always fall mulch my garlics. This year it didn't get done, not last year either, and I had almost perfect stands last spring anyway. It will be even more effective to spring mulch to keep soil moisture uniform for best top growth. Once again summer mulch also has to breath since garlic required good drainage.