On OpenBSD, drivers are named after the vendor & chipset they support,
rl(4) is for the cards based on the Realtek 8129/8130 chipset.
If your dmesg only shows a single rl0 device, then another driver is being used for the additional card.
You can look through the dmesg, or with
ifconfig(8) to find what cards are in your system.
In your example, you state rl0 but create a file named
hostname.rl1, perhaps that was a typo?