I do not understand your question, perhaps due to its unusual use of specific terminology?
You mentioned using MIDI and not usbMIDI. Presumably that means you're Francois Best's library? That would be regular 31250 baud serial MIDI.
The term "class-compliant" is specific to USB MIDI implementations. USB is a very complex protocol which implements numerous abstractions, like 16 endpoints, 4 transfer types, descriptors, and many other details. Which endpoints, which transfer type, what numbers to use in the descriptors and lots of other details can be chosen any number of ways. You don't simply send multi-byte messages from an OUT port and receive them on an IN port with USB. The USB protocol is extremely flexible and quite complex, so a lot of decisions need to made about how to use its features for MIDI.
A USB MIDI implementation is called "class compliant" when it follows the specifications in the USB audio class specs, specifically the "Universal Serial Bus Device Class Definition for MIDI Devices" release 1.0 published by the USB-IF on Nov 1, 1999. Among other things, that spec requires the normal 2 and 3 byte MIDI messages packed into 32 bit fields, and lengthy sysex messages packed with 1 to 3 bytes into similar 32 bit fields, with an additional byte specifying the message type (in some cases redundantly) and a virtual cable number.
Numerous USB MIDI implementations used other (probably simpler) approaches, mostly before this spec was published and the major operating systems provided drivers. In those cases, where MIDI is not "class compliant", the way the messages are packed into USB packets, which endpoints and transfer types are used, and how the descriptors look are all at the whim of the manufacturer (who must obviously provide their own driver).
So it is meaningless to talk of "class compliant" with ordinary serial MIDI. The protocol for regular serial MIDI is very well defined. Francois's library follows that protocol very well.
Teensy's usbMIDI implementation, by the way, is indeed class compliant. I am not aware of any conformance test to prove MIDI class compliance, but I can tell you I wrote the code using the USB-IF's audio class spec and I made every attempt to follow the specification. It's been used successfully by many people with the built-in drivers on Mac, Linux and Windows, so if I made any mistakes that are not strictly class compliant, they would likely be as-yet-to-be-discovered bugs that are extremely rare.
About your project, one thing you might try is reducing those 220 ohm resistors to 47 or 56 ohms, because Teensy 3.0 uses 3.3 volt signals. You mentioned only 1 resistor, but normally transmitting is done with 2 resistors... 1 on the signal and a second connected to Vcc. If you haven't connected the other pin through a resistor to Vcc (3.3 volts on Teensy 3.0), that might also be something to check.