## No: the arrows are not magical

The Sage Advice Compendium provides clear criteria when something counts as magical:, namely if you can answer yes to one of these questions:

> - Is it a magic item?
> - Is it a spell? Or does it let you create the effects of a spell
that’s mentioned in its description?
> - Is it a spell attack?
> - Is it fueled by the use of spell slots?
> - Does its description say it’s magical?

In the case of the magical bow, which is a magic weapon, the description for magic weapons (provided in an erratum, p. 140 DMG) explicitly states the arrows count as magical: 

> If a magic weapon has the ammunition property, **ammunition fired from it is considered magical** for the purpose of overcoming resistance and immunity to nonmagical attacks and damage.

fulfilling the last of these conditions. The *bracers of archery* are not a **magic weapon**, they are a **wondrous item** (p. 156 DMG):

> BRACERS OF ARCHERY\
*Wondrous item, uncommon (requires attunement)*

so they have no such language attached to them, and do not state the arrows are magical. 

The arrows themselves are also not a magic item, spell, spell attack nor are they fueled by spell slots, and the bracers do not make them any of that either, they just add +2 to damage. Ergo, they do not make the arrows magical.