Pre-order bonuses from different regions won't work on your home region's console.
While the base Grand Theft Auto 5 game will be essentially region-free (only the Japanese Xbox 360 edition of the game will be region-locked), DLC packs, including pre-order bonuses, may not be. Rockstar has released an official statement on its website regarding languages and region-locks, and it has revealed that DLC codes purchased in a region that differs from where you registered your PSN account may not be redeemable.
"It is generally recommended that you buy and play games that are designated for your country to avoid potential problems with DLC region-compatibility, such as with pre-order bonuses," says Sony. It offers the following example:
"A North American PS3 GTA V disc (BLUS31156 code on spine of box), Japanese PS3 GTA V disc (BLJM61019 code on the spine of the box) or Asian PS3 disc (BLAS 50639 code on spine of box for Singapore, Hong Kong, Taiwan. BLKS20442 for Korea) will play on a European PlayStation®3 console. However, if you live in Europe (where the GTAV disc code is BLES01807) you will likely have a European PSN account that will not be able to redeem a US pre-order code, and will only be able to download Region 2 (European) DLC, incompatible with non-European discs."
This applies to both the pre-order bonuses that are included in the various special editions for the game, as well as any future DLC packs released for the game. A work-around for this would be to say, import a European copy and then create a new European PSN account to register the pre-order DLC.
Something to keep in mind if you live in a country where videogame prices are exorbitantly high (*cough*Australia) and were planning on importing.
Source: Rockstar Games