If you're given the voucher, the points should credit immediately after you enter all your details into the redemption website.

If the hotel is going to credit the points to you, it varies. Some put it through overnight, so you'll see it in the morning in your account, some seem to do it once a week, and some seem to forget I've found that if the points don't show up, a quick email to the hotel 2 weeks later normally gets the bonus points posted that day, with an appology reply email around the same time.

Spain seems to be a bit special though... I've stayed at two Spanish hotels where the choice was only a drink, no points offered or available, but in those cases I was given a laminated drink voucher at checkin. One other one gave me a sealed envelope with the welcome letter in, which I'd assumed would have the drink voucher, but it didn't. Asked at reception, and they just rang the bar then told me to head to the bar and have a free drink, all very ad-hoc!