Hi Glen,
Bank accounts for foreigners in Serbia are now a bit tricky due to changes in banking laws a year or so ago. I bank with Intesa and have had a few issues.
As a foreigner, whilst you can transfer money into Serbia it's a different matter transferring out. Equally, you will find that, whilst you can make online payments using you visa card, you won't be able to make a payment from your online banking, even to a Serbian company, at least using the mobile phone app. It's a nightmare.
Also be aware that, if you pay anything from your Serbian RSD account to anywhere outside of Serbia, your money will first of all be converted into euros (a charge for that) and then from euros into whatever currency you are supposed to pay in (GBP or $ for example.... and of course, another charge for that).