There are a couple of issues, and they can make your trip difficult or not.

1. IB doesn't use the normal Amadeus PNR that every other airline uses. You'll get a 5-digit PNR that is only recognized by their website. If you're flying purely IB metal as in your case it's not likely to be a problem. If you have a mixed itin with say AA or BA flights...online checkin is probably going to fail. If you're flying to the US, the advance passenger information will fail to sync and you'll have to go through the documentation process again at the airport. Not the end of the world, but better if it didn't happen. IB do add a second six-digit PNR in those cases but it isn't obvious nor easy to find.

2. IB use the Spanish convention of one first name and two last names in their PNRs. The correct way to put a non-Spanish name in their system is FIRSTNAME MIDDLENAME as the first name, and LASTNAME as the first last name. If you don't do it this way, your flights won't credit to BA.

Also, if you happen to have an IB+ account, be absolutely sure to use an incognito window when making your booking, or no matter how many times you check and double-check that you have put in your BA number, the flights will mysteriously credit to IB and it takes an absurd amount of time and effort to get it fixed.