Sigil of Renewal scaling with Sigil of Transference

So the healing calculation for Sigil of Renewal is 345 + 04 * Healing Power (Source: Wiki) and the Sigil of Transference (Wiki) adds a 10% effectiveness increase to outgoing healing.Does this boost affect the Sigil of Renewal and how does the calculation there work? I remember that damage modifiers are not additive, is this also true for the healing modifiers?

So would it be: (345 + 04 Healing Power)1.1

Cheers

Edit: Checked ingame with the sigil being the only boost. Expected healing with the above calculation is 1018.38, ingame I got 1019, GW2 always rounds up. So the question left now is how multiple healing boosts add up.