Iran changes to foreign bank cards/online hotel reservations after sanctions lifted?

Me think it will take some times before all the banking and tourist/hotel infrastructure gets up to par with the rest of the world.

1. Banks/Credit cards/ATM/Debit cards: I assume they will need to get some sort of international accreditation to allow PLUS/Cirrus/Maestro networking and other basic international banking service to be common in Iran.

2. Hotels: Most (all?) large hotel chains are absent in Iran, so they do not have the online/offline booking services that we have elsewhere. Once big hotel chains see there is money to be made in Iran, then you will see more and more online booking available, not only from big chains, but also from small independent hotels.

For now, and the next couple of months (years?) I imagine nothing will change for regular travelers.

To give a counter voice to Max' answer, I actually think that online booking will be available very quickly. Not for large hotel chains, but for services like AirBNB and Hostelworld. Plenty of Iranians have accounts abroad but now, American law no longer prevents American businesses from doing business with Iran.

I'm not sure if the link will hold, but some properties seem to already be bookable online. Here's one.

As far as international banking is concerned, I'm reasonably sure that the Iranian banking system has been connected to the rest of the world for years. The connection could just not be used because of sanctions. So, here, too, I think things will changes reasonably quickly. Credit card payments within Iran might take a bit longer to get off the ground, but using ATMs with foreign cards will be available sooner.

My estimate is that, before the end of the year, some ATMs in Iran will work with international cards and most big cities will offer competitive accommodation that will be bookable online.