The issues with wholemeal, as I understand it, aren't about gluten/wheat, but about too much fibre for an immature digestive system.
This. The whole grain is too difficult for an immature gut to digest, plus whole grains are too filling which puts a risk on milk intake and milk is their primary food source.
That said, I gave mine whole meal bread in small amounts rather than buying a whole white loaf which wouldn't be eaten. But I gave him other baked goods which were white not whole grain, bread sticks, crackers, naan bread, tortilla wraps, crumpets, home made pancakes, home made muffins (sugar free), white pasta...
Sweet potatoes are a great alternative, carbs but more nutritious than white potatoes. yummy too
I also made oaty chews which are kind of like a flap jack but without any sugar, honey or syrup.