Do consumers owning an iPhone convert better? Yes, in some
product-cases they do
It’s possible to target tablets and/or phones. It’s possible to target specific brands of phones and tablets.
It’s even possible to target specific models (or versions) of phones and tablets. Many campaign options arise by deploying this technology. For example; serving an offer (ad/banner) of the newest iPhone/Samsung to/on models that are 2 years old (indicating a new phone might be bought soon).