Is an entire /24 network typically used for vIPs in an F5 deployment?

Going with one client-side /24 subnet for all VIPs is generally better. Future scaling is possible, you will just have to make it a /23 network if you run out of IP addresses. It's not a problem if your servers are in different networks, you can establish connectivity to various server-side networks by configuring selfIPs on BigIP; by doing so you will make F5 a participant in all the networks where your Pool Members are going to be in.

So if your question is whether or not you can use the same client-side VIP subnet for all your services that reside in different back-end (server-side) networks, the answer is yes you can.