Hello @Salves ,
I checked with the backend team and there is no Tier field/option for Public IP creation and looks like enabling Bastion while Vnet creation blade had a Portal bug where it was probing for a Tier while creating Public IP. However, it has been removed now and it should not prompt you for that field anymore.
You can now enable BastionHost while creating a Virtual Network just as described in Bastion Host creation article:
https://video2.skills-academy.com/en-us/azure/bastion/bastion-create-host-portal
Kindly let us know if the above helps or you need further assistance on this issue.
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